SOUTHWEST GAS CORPORATION $300,000,000 3.80% Senior Notes due 2046 UNDERWRITING AGREEMENT

Exhibit 1.1

EXECUTIVE VERSION

SOUTHWEST GAS CORPORATION

$300,000,000 3.80% Senior Notes due 2046

UNDERWRITING AGREEMENT

September 26, 2016

BNY Mellon Capital Markets, LLC

▇.▇. ▇▇▇▇▇▇ Securities LLC

▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇

Incorporated

▇▇▇▇▇ Fargo Securities, LLC

as Representatives of the Underwriters named in Schedule 1

▇/▇ ▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇, LLC

▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇

▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

c/o ▇.▇. ▇▇▇▇▇▇ Securities LLC

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▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

c/o Merrill Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇

Incorporated

▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇

▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

c/o Wells Fargo Securities, LLC

▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇

▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇

Ladies and Gentlemen:

Southwest Gas Corporation, a California corporation (the “Company”), proposes to issue and sell to the several underwriters (the “Underwriters”) named in Schedule 1 attached to this agreement (this “Agreement”) acting severally and not jointly, the respective amounts set forth in such Schedule 1 of $300,000,000 aggregate principal amount of its 3.80% Senior Notes due 2046 (the “Securities”). The Securities will be issued pursuant to an Indenture dated as of September 29, 2016 (the “Indenture”) between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”). This is to confirm the agreement concerning the purchase of the Securities from the Company by the Underwriters.

1. Representations, Warranties and Agreements of the Company. The Company represents, warrants and agrees that:

(a) A Registration Statement (as defined below) on Form S-3 relating to the Securities (i) has been prepared by the Company in conformity with the requirements of the Securities Act of 1933, as amended (the “Securities Act”), and the rules and regulations (together, the “Rules and Regulations”) of the Securities and Exchange Commission (the “Commission”) thereunder; (ii) has been filed with the Commission under the Securities Act; and (iii) is effective under the Securities Act. Copies of such Registration Statement and any amendment thereto have been delivered by the Company to BNY Mellon Capital Markets, LLC, ▇.▇. ▇▇▇▇▇▇ Securities LLC, ▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated and ▇▇▇▇▇ Fargo Securities, LLC, as the representatives (“you” or the “Representatives”) of the Underwriters. For the avoidance of doubt, the availability to the Underwriters of such Registration Statement and any amendment thereto on the Commission’s ▇▇▇▇▇ database shall satisfy the Company’s delivery obligation with respect thereto. As used in this Agreement:

(i) “Applicable Time” means September 26, 2016 at 3:00 p.m. (New York City time);

(ii) “Effective Date” means any date as of which any part of such registration statement relating to the Securities became, or is deemed to have become, effective under the Securities Act in accordance with the Rules and Regulations;

(iii) “Issuer Free Writing Prospectus” means each “issuer free writing prospectus” (as defined in Rule 433(h) of the Rules and Regulations) prepared by or on behalf of the Company or used or referred to by the Company in connection with the offering of the Securities, including each “road show” (as defined in Rule 433(h) of the Rules and Regulations) relating to the offering of the Securities that is a “written communication” (as defined in Rule 405 under the Rules and Regulations);

(iv) “Preliminary Prospectus” means the preliminary prospectus, dated September 26, 2016, specifically relating to the Securities that is included in the Registration Statement at the time of its effectiveness and that omits Rule 430 Information;

(v) “Pricing Disclosure Package” means, as of the Applicable Time, the Preliminary Prospectus, together with the information included in Schedule 2 hereto and each Issuer Free Writing Prospectus filed or used by the Company on or before the Applicable Time, other than any road show that is an Issuer Free Writing Prospectus;

(vi) “Prospectus” means the final prospectus, dated September 26, 2016 relating to the Securities, as filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations (“Rule 424(b)”); and

(vii) “Registration Statement” means, collectively, the various parts of the registration statement on Form S-3 relating to the Securities (File No. 333-213787), each as amended as of the Effective Date for such part, including the Preliminary Prospectus or the Prospectus, the information, if any, deemed pursuant to Rule 430A, 430B or 430C under the Securities Act to be part of the registration statement at the time of its effectiveness and all exhibits to such registration statement (“Rule 430 Information”).

Any reference to the Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Form S-3 under the Securities Act as of the date of the Preliminary Prospectus or the Prospectus, as the case may be; any reference to the Registration Statement shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Form S-3 under the Securities Act as of the date of this Agreement; and all references to information that is “included” or “contained” in the Preliminary Prospectus, the Prospectus, the Registration Statement or the Pricing Disclosure Package (and any similar references) shall mean and include all information that is incorporated by reference therein pursuant to Form S-3 under the Securities Act. Any reference to any amendment or supplement to the Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any document filed under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), after the date of the Preliminary Prospectus or the Prospectus, as the case may be, and incorporated by reference in the Preliminary Prospectus or the Prospectus, as the case may be; and any reference to any amendment to the Registration Statement shall be deemed to refer to any document filed under the Exchange Act after the date of this Agreement that is incorporated by reference in the Registration Statement. The Commission has not issued any order preventing or suspending the use of the Preliminary Prospectus or the Prospectus or suspending the effectiveness of the Registration Statement, and no proceeding or examination for such purpose has been instituted or, to the Company’s knowledge, threatened by the Commission. The Commission has not notified the Company of any objection to the use of the form of the Registration Statement.

(b) The Company has been since the time of the initial filing of the Registration Statement and continues to be a “well-known seasoned issuer” (as defined in Rule 405 of the Rules and Regulations) eligible to use Form S-3 for the offering of the Securities, including not having been an “ineligible issuer” (as defined in Rule 405 of the Rules and Regulations) at any such time or date. The Registration Statement is an “automatic shelf registration statement” (as defined in Rule 405 of the Rules and Regulations) and was filed not earlier than the date that is three years prior to the Closing Date (as defined in Section 4 hereof).

(c) The Registration Statement conformed and will conform in all material respects on the Effective Date and on the Closing Date, and any amendment to the Registration Statement filed after the date hereof will conform in all material respects when filed, to the requirements of the Securities Act, the Rules and Regulations and the Trust Indenture Act of 1939, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Trust Indenture Act”). The Prospectus will conform, in all material respects when filed with the Commission pursuant to Rule 424(b) and on the Closing Date to the requirements of the Securities Act and the Rules and Regulations. The documents incorporated by reference in the Preliminary Prospectus or the Prospectus conformed, and any further documents so incorporated will conform, when filed with the Commission, in all material respects to the requirements of the Exchange Act or the Securities Act, as applicable, and the rules and regulations of the Commission thereunder.

(d) The Registration Statement did not, as of the Effective Date, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; provided that no representation or warranty is made as to information contained in or omitted from the Registration Statement in

reliance upon and in conformity with (i) written information furnished to the Company through the Representatives by or on behalf of any Underwriters specifically for inclusion therein, which information is specified in Section 8(e) hereof and (ii) that part of the Registration Statement that constitutes the Statement of Eligibility and Qualification (the “Form T-1”) of the Trustee under the Trust Indenture Act.

(e) The Prospectus does not and will not, as of its date and on the Closing Date, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that no representation or warranty is made as to information contained in or omitted from the Prospectus in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriters specifically for inclusion therein, which information is specified in Section 8(e) hereof.

(f) The documents incorporated by reference in the Preliminary Prospectus or the Prospectus did not, and any further documents filed and incorporated by reference therein will not, when filed with the Commission, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(g) The Pricing Disclosure Package did not, as of the Applicable Time, contain an untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that no representation or warranty is made as to information contained in or omitted from the Pricing Disclosure Package in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriters specifically for inclusion therein, which information is specified in Section 8(e) hereof.

(h) Each Issuer Free Writing Prospectus (including, without limitation, any road show that is a free writing prospectus under Rule 433 of the Rules and Regulations), when considered together with the Pricing Disclosure Package as of the Applicable Time, did not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that no representation or warranty is made as to information contained in or omitted from any Issuer Free Writing Prospectus in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriters specifically for inclusion therein, which information is specified in Section 8(e) hereof.

(i) Each Issuer Free Writing Prospectus conformed or will conform in all material respects to the requirements of the Securities Act and the Rules and Regulations on the date of first use, and the Company has complied or will comply, as applicable, with any filing requirements applicable to such Issuer Free Writing Prospectus pursuant to the Rules and Regulations. The Company has not made any offer relating to the Securities that would constitute an Issuer Free Writing Prospectus without the prior written consent of the

Representatives (such consent not to be unreasonably delayed or withheld). The Company has retained in accordance with the Rules and Regulations all Issuer Free Writing Prospectuses that were not required to be filed with the Commission pursuant to the Rules and Regulations. No Issuer Free Writing Prospectus conflicted with or will conflict with the information in the Registration Statement, the Preliminary Prospectus or the Prospectus.

(j) Each of the Company and its subsidiaries listed on Schedule 3 hereto (herein called, collectively, the “Significant Subsidiaries”) (A) has been duly incorporated, organized or formed and is validly existing in good standing under the laws of the jurisdiction of its incorporation, organization or formation, with full power and authority to own, lease and operate its properties and conduct its business; and (B) is duly registered and qualified to do business and is in good standing in each jurisdiction in which the character of the business conducted by it or the location of the properties owned, leased or operated by it make such registration or qualification necessary, except, as it relates to this clause (B), for such jurisdictions where the failure to so register, qualify or to be in good standing would not, individually or in the aggregate, have a Material Adverse Effect (as defined below). Except for the subsidiaries listed on Schedule 4 hereto, the Company does not have any subsidiaries or control, directly or indirectly, any corporation, association or other entity other than the Significant Subsidiaries. Other than the Significant Subsidiaries, (i) no subsidiary of the Company is a “significant subsidiary” (as defined in Rule 405 of the Rules and Regulations) and (ii) no two or more subsidiaries of the Company considered in the aggregate constitute a “significant subsidiary” (as defined in Rule 405 of the Rules and Regulations).

(k) The authorized, issued and outstanding common stock, par value $1.00 per share (the “Common Stock”), and other capital stock of the Company is as set forth in each of the Preliminary Prospectus and the Prospectus (except for subsequent issuances, if any, of Common Stock pursuant to employee or director equity incentive or stock purchase plans). The shares of issued and outstanding Common Stock have been duly authorized, validly issued, fully paid and non-assessable and were issued in compliance with federal and state securities laws. All of the outstanding shares of capital stock of each Significant Subsidiary that is a corporation have been duly authorized and validly issued and are fully paid and non-assessable. Except as may otherwise be disclosed in the Pricing Disclosure Package and in the Prospectus, all of the outstanding shares of capital stock, partnership interests or other ownership interests of each Significant Subsidiary are owned directly or indirectly by the Company, free and clear of any claim, lien, encumbrance, security interest, restriction upon voting or transfer, preemptive rights or any other claim of any third party (collectively, “Liens”), except such Liens as would not, individually or in the aggregate, reasonably be expected to have a material adverse effect on the condition (financial or otherwise), results of operations, properties or business of the Company and its subsidiaries taken as a whole or on the performance by the Company of this Agreement (a “Material Adverse Effect”).

(l) The Indenture has been duly authorized by the Company and, upon effectiveness of the Registration Statement, was or will have been duly qualified under the Trust Indenture Act and, when duly executed and delivered in accordance with its terms by each of the parties thereto, will constitute a valid and legally binding agreement of the Company, enforceable against the Company in accordance with its terms, except as enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent

conveyance, usury, stay, extension or other similar laws affecting the enforcement of creditors’ rights generally or by general equitable principles relating to enforceability (collectively, the “Enforceability Exceptions”).

(m) The Securities have been duly authorized by the Company and, when duly executed, authenticated, issued and delivered as provided in the Indenture and paid for as provided herein, will be duly and validly issued and outstanding and will constitute valid and legally binding obligations of the Company, entitled to the benefits of the Indenture and enforceable against the Company in accordance with their terms, subject to the Enforceability Exceptions.

(n) The Company has all requisite corporate power and authority to execute, deliver and perform its obligations under this Agreement, the Securities and the Indenture (collectively, the “Transaction Documents”). This Agreement has been duly authorized, executed and delivered by the Company.

(o) None of the execution, delivery and performance of the Transaction Documents by the Company, the issuance, sale and delivery of the Securities by the Company, compliance by the Company with any of the provisions of the Transaction Documents nor the application of the proceeds from the sale of the Securities as described under “Use of Proceeds” in the Pricing Disclosure Package and the Prospectus will (i) conflict with or result in a breach or violation of any agreement, indenture or other instrument to which the Company or any of its subsidiaries is a party or by which any of them is bound, or to which any of their properties is subject; (ii) result in the creation or imposition of any Lien upon any property or asset of the Company or any of its subsidiaries; (iii) result in a breach or violation of, or constitute a default under, the articles of incorporation, by-laws, partnership agreement or other organizational documents of the Company or any of its Significant Subsidiaries; or (iv) violate any law, rule, administrative regulation or decree of any court or any governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their respective properties, except, with respect to clauses (i), (ii) and (iv), conflicts, breaches, Liens, defects or violations that would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect.

(p) No permit, consent, approval, authorization or order of any court, governmental agency or body (including the Federal Energy Regulatory Commission) or financial institution is required for the issue and sale of the Securities, the execution, delivery and performance of the Transaction Documents by the Company, or the application of the proceeds from the sale of the Securities as described under “Use of Proceeds” in the Pricing Disclosure Package and the Prospectus, except (i) for the registration of the Securities under the Securities Act; (ii) for the qualification of the Indenture under the Trust Indenture Act; (iii) from the Public Utilities Commission of the State of California; (iv) such consents, approvals, authorizations, orders, filings, registrations or qualifications as may be required under the Exchange Act and applicable state or foreign securities laws in connection with the purchase and sale of the Securities through the Underwriters; and (v) where the failure to obtain such permits, consents, approvals, authorizations, orders, filings, registrations or qualifications would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(q) There are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company owned or to be owned by such person or to require the Company to include such securities in the securities registered pursuant to the Registration Statement or in any securities being registered pursuant to any other registration statement filed by the Company under the Securities Act.

(r) The Company has not sold or issued any securities that would be integrated with the offering of the Securities contemplated by this Agreement pursuant to the Securities Act, the Rules and Regulations or the interpretations thereof by the Commission.

(s) Since the date of the latest audited financial statements included or incorporated by reference in the Pricing Disclosure Package and the Prospectus, neither the Company nor any of its subsidiaries has (i) sustained any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree; (ii) issued or granted any securities (other than the shares of capital stock issued pursuant to employee benefit plans, qualified stock option plans or other employee compensation plans existing on the date hereof or pursuant to currently outstanding equity awards, warrants or rights not issued under one of those plans), except as may otherwise be disclosed in the Pricing Disclosure Package and in the Prospectus; (iii) incurred any liability or obligation, direct or contingent, other than liabilities and obligations that were incurred in the ordinary course of business, except as may otherwise be disclosed in the Pricing Disclosure Package and in the Prospectus; (iv) entered into any transaction not in the ordinary course of business, except as may otherwise be disclosed in the Pricing Disclosure Package and in the Prospectus; (v) declared or paid any dividend on its capital stock (other than Common Stock dividends paid on March 1, June 1 and September 1, 2016); or (vi) made or experienced any change in the capital stock or long-term debt of the Company or any of its subsidiaries or any adverse change, or any development involving a prospective adverse change, in or affecting the condition (financial or otherwise), results of operations, properties or business of the Company and its subsidiaries taken as a whole, in each case in this paragraph (s) (except clause (v) hereof) as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(t) The financial statements (including the related notes and supporting schedules) included or incorporated by reference in the Pricing Disclosure Package and the Prospectus present fairly in all material respects the consolidated financial condition, results of operations and cash flows of the entities purported to be shown thereby at the dates and for the periods indicated (subject to year-end adjustments in the case of unaudited interim financial statements) and have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) applied on a consistent basis throughout the periods indicated and conform in all material respects with GAAP, except as otherwise noted therein; and the supporting schedules included or incorporated by reference in the Registration Statement present fairly in all material respects the information required to be stated therein. The interactive data in eXtensbile Business Reporting Language included or incorporated by reference in the Registration Statement, the Pricing Disclosure Package, and the Prospectus fairly presents the information called for in all material respects and has been prepared in accordance with the Commission’s rules and guidelines applicable thereto.

(u) PricewaterhouseCoopers LLP, who have reported on certain financial statements of the Company included or incorporated by reference in the Pricing Disclosure Package and the Prospectus and whose report is incorporated by reference in the Preliminary Prospectus and the Prospectus, are independent registered public accountants as required by the Securities Act and the Rules and Regulations, and were independent public accountants as required by the Securities Act and the Rules and Regulations during the periods covered by the financial statements on which they reported contained or incorporated by reference in the Registration Statement, the Pricing Disclosure Package and the Prospectus.

(v) The statistical and market-related data, if any, included in the Pricing Disclosure Package and the Prospectus and the consolidated financial statements of the Company and its subsidiaries included or incorporated by reference in the Pricing Disclosure Package and the Prospectus are based on or derived from sources that the Company believes to be reliable and accurate in all material respects.

(w) Neither the Company nor any of its subsidiaries is, and as of the Closing Date and, after giving effect to the offer and sale of the Securities and the application of the proceeds therefrom as described under “Use of Proceeds” in the Pricing Disclosure Package and the Prospectus, none of them will be, an “investment company” within the meaning of such term under the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder.

(x) There is no litigation or governmental proceeding to which the Company or any of its subsidiaries is a party or to which any property or assets of the Company or any of its subsidiaries is subject or which is pending or, to the knowledge of the Company, threatened against the Company or any of its subsidiaries that would, individually or in the aggregate, reasonably be expected to result in a Material Adverse Effect.

(y) There are no statutes or regulations, legal or governmental proceedings or contracts or other documents that would be required to be described in the Registration Statement, the Pricing Disclosure Package or the Prospectus (in each case including, without limitation, the documents incorporated by reference therein) or, in the case of contracts or other documents, to be filed as exhibits to the Registration Statement, that are not described and filed as required under applicable law.

(z) To the knowledge of the Company, no labor disturbance by or dispute with the employees of the Company or any of its subsidiaries exists or is imminent that would reasonably be expected to have a Material Adverse Effect.

(aa) (i) Except as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect, the Company and each of its subsidiaries and any “employee benefit plan” (as defined under the U.S. Employee Retirement Income Security Act of 1974, as amended (“ERISA,” which term, as used herein, includes the regulations and published interpretations thereunder)) established or maintained by the Company, any of its subsidiaries or their ERISA Affiliates (as defined below) are in compliance in all material respects with ERISA and, to the knowledge of the Company, each “multiemployer plan” (as defined in Section 4001 of ERISA) to which the Company, its subsidiaries or an ERISA Affiliate

contributes (a “Multiemployer Plan”) is in compliance in all material respects with ERISA. “ERISA Affiliate” means, with respect to the Company or a subsidiary, any member of any group of organizations described in Section 414 of the U.S. Internal Revenue Code of 1986, as amended (the “Code,” which term, as used herein, includes the regulations and published interpretations thereunder) of which the Company or such subsidiary is a member. No “reportable event” (as defined under ERISA) has occurred or is reasonably expected to occur with respect to any “employee benefit plan” established or maintained by the Company, any of its subsidiaries or any of their ERISA Affiliates. Neither the Company, any of its subsidiaries nor any of their ERISA Affiliates has incurred or reasonably expects to incur any liability under (i) Title IV of ERISA (other than contributions to the “employee benefit plan” or premiums to the U.S. Pension Benefit Guaranty Corporation in the ordinary course and without default) or (ii) Sections 412, 4971, 4975 or 4980B of the Code or pursuant to Section 406 of ERISA. Each “employee benefit plan” established or maintained by the Company, any of its subsidiaries or any of their ERISA Affiliates that is intended to be qualified under Section 401 of the Code is so qualified and nothing has occurred, whether by action or by failure to act, which would materially adversely affect such qualification.

(bb) The Company and each of its subsidiaries have filed all material federal, state, local and foreign tax returns required to be filed through the date hereof, subject to permitted extensions, which returns are complete and correct in all material respects, and have paid all taxes due, and neither the Company nor any subsidiary is in default in the payment of any taxes which were payable pursuant to said returns or any assessments with respect thereto, except for any such taxes or assessments which are being contested in good faith by appropriate proceedings and for which appropriate reserves, if any, have been established in accordance with GAAP and statutory accounting principles, and no tax deficiency has been determined adversely to the Company or any of its subsidiaries. The Company does not have any knowledge of any tax deficiencies that have been, or could reasonably be expected to be, asserted against the Company that would, in the aggregate, reasonably be expected to have a Material Adverse Effect.

(cc) Neither the Company nor any of its subsidiaries is in violation of its respective articles of incorporation or by-laws or other organizational documents, and neither the Company nor any of its subsidiaries (i) is in default, and no event has occurred which, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement, license or other agreement or instrument to which it is a party or by which it is bound or to which any of its properties or assets is subject or (ii) is in violation of any law, ordinance, rule, regulation or order of any court or governmental agency or body having jurisdiction over it or its property or assets, except in the case of clauses (i) and (ii), to the extent any such conflict, breach, violation or default would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(dd) The Company is and, to the knowledge of the Company, its officers and directors are, in compliance in all material respects with the ▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act of 2002 and the rules and regulations promulgated in connection therewith.

(ee) (i) Each of the Company and its subsidiaries holds such permits, licenses, patents, franchises, certificates of need, authorities and other approvals or authorizations from

governmental or regulatory authorities (collectively, the “Permits”) which are necessary under applicable law to the conduct of its businesses as presently operated and to own its properties and conduct its businesses in the manner described in the Pricing Disclosure Package and the Prospectus, except where the failure to obtain such Permits would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; (ii) each of the Company and its subsidiaries has fulfilled and performed all of its obligations necessary to maintain the Permits, except where the failure to fulfill or perform such obligations would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; and (iii) there is no past, pending or, to the knowledge of the Company or any of its subsidiaries, threatened action, suit, proceeding or investigation that may reasonably be expected to lead to the revocation, termination or suspension of any Permit, except where such revocation, termination or suspension would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. Neither the Company nor any of its subsidiaries has received notice of any revocation or modification of any such Permits or has any reason to believe that any such Permits will not be renewed in the ordinary course, except where such revocation, modification or non-renewal would not reasonably be expected to result in a Material Adverse Effect.

(ff) The Company and its subsidiaries own or possess, or have the ability to acquire, all patents, patent rights, licenses, inventions, copyrights, know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), trademarks, service marks and trade names currently employed by them in connection with the business now operated by them, except where the failure to own, possess or have the ability to acquire such patents, patent rights, licenses, inventions, copyrights, know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), trademarks, service marks and trade names would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect, and none of the Company nor its subsidiaries has received any notice of infringement of or conflict with asserted rights of others with respect to any of the foregoing which, individually or in the aggregate, if subject to any unfavorable decision, ruling or finding, would reasonably be expected to have a Material Adverse Effect.

(gg) The Company and its subsidiaries (i) are in compliance with any and all applicable foreign, federal, state and local laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (“Environmental Laws”); (ii) have received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses; and (iii) are in compliance with all terms and conditions of any such permit, license or approval, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(hh) Neither the Company nor any of its subsidiaries, nor, to the knowledge of the Company, any director, officer, agent, employee or other person acting on behalf of the Company or any of its subsidiaries, has (i) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity; (ii) made

any direct or indirect unlawful payment to any foreign or domestic government official or employee from corporate funds; or (iii) made any bribe or other unlawful payment.

(ii) Neither the Company nor any of its subsidiaries nor, to the Company’s knowledge, any director, officer, agent, employee or affiliate of the Company or any of its subsidiaries has taken any action, directly or indirectly, that would result in a violation by such persons of the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (the “FCPA”) or any other applicable anti-bribery or anti-corruption law, including, without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA, and the Company, its subsidiaries and, to the knowledge of the Company, its affiliates have conducted their businesses in compliance with the FCPA and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith.

(jj) The operations of the Company and its subsidiaries are and have been conducted at all times in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all applicable jurisdictions, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any applicable governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Money Laundering Laws is pending or, to the knowledge of the Company, threatened.

(kk) Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company, any director, officer, agent, employee or affiliate of the Company or any of its subsidiaries is currently subject to any sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”) or any sanctions imposed or administered by any other jurisdiction where the Company operates (collectively, “Sanctions”); and the Company will not directly or indirectly use the proceeds of the offering, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other person or entity, for the purpose of financing the activities of any person currently subject to any Sanctions.

(ll) The Company has not distributed and, prior to the later to occur of the Closing Date and completion of the distribution of the Securities, will not distribute any offering material in connection with the offering and sale of the Securities other than the Preliminary Prospectus, the Prospectus and any Issuer Free Writing Prospectus to which the Representatives have consented in accordance with Section 1(i) or 5(a)(vi) hereof (such consent not to be unreasonably withheld or delayed).

(mm) None of the Company, nor its subsidiaries or affiliates, has taken nor will take, directly or indirectly, any action designed to or that has constituted or that could reasonably

be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Securities.

(nn) The Company and its subsidiaries, on a consolidated basis, maintain systems of internal control over financial reporting (as such term is defined in Rule 13a-15(f) under the Exchange Act) that have been designed by, or under the supervision of, their respective principal executive and principal financial officers, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with GAAP and statutory accounting principles. The Company and its subsidiaries, on a consolidated basis, maintain a system of internal accounting controls sufficient to provide reasonable assurances that (i) transactions are executed in accordance with management’s general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and statutory accounting practices and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; (iv) interactive data in eXtensbile Business Reporting Language included or incorporated by reference in the Registration Statement, the Pricing Disclosure Package, and the Prospectus is prepared in accordance with the Commission’s rules and guidelines applicable thereto, and (v) recorded assets are compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(oo) The Company and its subsidiaries, on a consolidated basis, have established and maintain disclosure controls and procedures (as such term is defined in Rule 13a-15(e) under the Exchange Act) that have been designed to ensure that material information relating to the Company and its subsidiaries required to be disclosed in the reports the Company files or submits under the Exchange Act is made known to the Company’s principal executive officer and principal financial officer by others within those entities; and such disclosure controls and procedures are effective in all material respects to perform the functions for which they were established.

(pp) Since the date of the latest audited financial statements incorporated by reference in the Preliminary Prospectus, (i) the Company has not been advised of any fraud, whether or not material, that involves management or other employees who have a significant role in the internal controls of the Company and each of its subsidiaries and (ii) there have been no significant changes in internal controls or in other factors that would significantly affect internal controls, including any corrective actions with regard to significant deficiencies and material weaknesses requiring disclosure in the Company’s most recently filed Annual Report on Form 10-K.

(qq) The Company and each of its subsidiaries have good and marketable title in fee simple to all real property and good and marketable title to all personal property owned by them, in each case free and clear of all Liens, except where the failure to have such good and marketable title or the existence of any such Liens would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. All assets held under lease by the Company and its subsidiaries are held by them under valid, subsisting and enforceable leases with such exceptions as do not materially interfere with the use made and proposed to be made of such assets by the Company and its subsidiaries, except where the failure of any such leases to

be valid, subsisting or enforceable or the existence of such exceptions would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(rr) No relationship, direct or indirect, exists between or among the Company, on the one hand, and the directors, officers, shareholders, customers or suppliers of the Company, on the other hand, that is required to be described in the Pricing Disclosure Package or the Prospectus which is not so described.

(ss) The statements set forth in the Preliminary Prospectus and the Prospectus under the captions “Description of Other Indebtedness,” “Description of the Notes,” and “Material United States Federal Income Tax Considerations,” insofar as they purport to describe the Securities, and other documents and legal matters referred to therein, are accurate in all material respects.

(tt) Neither the Company nor any of its subsidiaries is a party to any contract, agreement or understanding with any person (other than this Agreement) that would give rise to a valid claim against any of them or the Underwriters for a brokerage commission, finder’s fee or like payment in connection with the offering and sale of the Securities.

(uu) None of the proceeds from the sale of the Securities has been or will be paid to the Underwriters (except for the payment of the commissions pursuant to this Agreement) or, to the knowledge of the Company, to any affiliate of the Underwriters; and the Company is not an “affiliate” (as defined in FINRA Rule 5121) of any member of the Financial Industry Regulatory Authority (“FINRA”).

(vv) The Company and its subsidiaries are in compliance with, and conduct their respective businesses in conformity with, all applicable state, federal, local and foreign laws and regulations relating to the operation and ownership of a public utility, including, without limitation, those relating to the distribution and transmission of natural gas, except to the extent that any failure so to comply or conform would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(ww) Each of the Company and its subsidiaries believes they are insured with policies in such amounts and with such deductibles and covering such risks as are generally deemed adequate and customary for their businesses, including, but not limited to, insurance against accidents, third-party injury or general liability and insurance covering certain real and personal property owned or leased by the Company and each of its subsidiaries against theft, damage, destruction, acts of vandalism and all other risks customarily insured against. All policies of insurance insuring the Company or any of its subsidiaries or their respective businesses, assets, employees, officers and directors are in full force and effect; the Company and its subsidiaries are in compliance with the terms of such policies and instruments in all material respects; and there are no claims by the Company or any of its subsidiaries, that individually or in the aggregate are material to the Company and its subsidiaries taken together as a whole, under any such policy or instrument as to which any insurance company is denying liability or defending under a reservation of rights clause; and, except as set forth in the Pricing Disclosure Package and the Prospectus, neither the Company nor any of its subsidiaries has been refused any insurance coverage sought or applied for. The Company has no reason to believe that

it or any of its subsidiaries will not be able (i) to renew its existing insurance coverage as and when such policies expire or (ii) to obtain comparable coverage from similar institutions as may be necessary or appropriate to conduct its business as now conducted and at a cost that would not reasonably be expected to have a Material Adverse Effect.

Any certificate signed by any officer of the Company and delivered to the Underwriters or counsel for the Underwriters in connection with the offering of the Securities shall be deemed a representation and warranty by the Company to each Underwriter as to matters covered thereby.

2. Purchase of the Securities by the Underwriters. On the basis of the representations and warranties contained in, and subject to the terms and conditions of, this Agreement, the Company agrees to sell the Securities at a price equal to 98.823% of the aggregate principal amount thereof, plus accrued interest, if any, from September 29, 2016, to the several Underwriters, and each of the Underwriters, severally and not jointly, agrees to purchase the principal amount of the Securities set forth opposite that Underwriter’s name in Schedule 1 hereto.

The Company shall not be obligated to deliver any of the Securities to be delivered on the Closing Date, except upon payment for all such Securities to be purchased on such Closing Date as provided herein.

3. Offering of Securities by the Underwriters. Upon authorization by the Representatives of the release of the Securities, the several Underwriters propose to offer the Securities for sale upon the terms and conditions to be set forth in the Prospectus.

4. Delivery of and Payment for the Securities. Delivery of and payment for the Securities shall be made at 10:00 a.m. New York City time, on September 29, 2016 or at such other date or place as shall be determined by agreement between the Representatives and the Company. This date and time are sometimes referred to as the “Closing Date.” Delivery of the Securities shall be made to the Representatives against payment by the several Underwriters through the Representatives of the respective aggregate purchase prices of the Securities being sold by the Company by wire transfer in immediately available funds to the accounts specified by the Company. Time shall be of the essence, and delivery at the time and place specified pursuant to this Agreement is a further condition of the obligation of each Underwriter hereunder. The Company shall deliver the Securities through the facilities of Depository Trust Company unless the Representatives shall otherwise instruct.

5. Further Agreements of the Company and the Underwriters.

(a) The Company agrees:

(i) To prepare the Prospectus in a form approved by the Representatives and to file such Prospectus pursuant to Rule 424(b) not later than the Commission’s close of business on the second business day following the execution and delivery of this Agreement; to make no further amendment or any supplement to the Registration Statement or the Prospectus prior to the Closing Date except as provided herein; to advise the Representatives in writing, promptly after it receives notice thereof, of the time when any

amendment or supplement to the Registration Statement or the Prospectus has been filed and to furnish the Representatives with copies thereof; to file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of the Prospectus and for so long as the delivery of a prospectus is required in connection with the offering or sale of the Securities; to advise the Representatives in writing, promptly after it receives notice thereof, of the issuance by the Commission of any stop order or of any order preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus, of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding or examination for any such purpose, of any notice from the Commission objecting to the use of the form of the Registration Statement or any post-effective amendment thereto or of any request by the Commission for the amending or supplementing of the Registration Statement, the Prospectus or any Issuer Free Writing Prospectus or for additional information; and, in the event of the issuance of any stop order or of any order preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus or suspending any such qualification, to use promptly its reasonable best efforts to obtain its withdrawal;

(ii) To pay the applicable Commission filing fees relating to the Securities within the time required by Rule 456(b)(1) of the Rules and Regulations without regard to the proviso therein;

(iii) To deliver promptly to the Representatives such number of written or electronic copies of the following documents as the Representatives shall reasonably request: (A) conformed copies of the Registration Statement as originally filed with the Commission and each amendment thereto (in each case excluding exhibits other than this Agreement, the computation of ratio of earnings to fixed charges and the portions of the annual report to shareholders incorporated by reference into the Company’s Form 10-K for the year ended December 31, 2015), (B) the Preliminary Prospectus, the Prospectus and any amended or supplemented Prospectus, (C) each Issuer Free Writing Prospectus and (D) any document incorporated by reference in the Preliminary Prospectus or the Prospectus, it being understood that with regard to (A) and (D) above, availability to the Underwriters on the Commission’s ▇▇▇▇▇ database of the documents referenced therein shall satisfy any such delivery obligations with respect thereto; and, if the delivery of a prospectus is required at any time after the date hereof in connection with the offering or sale of the Securities or any other securities relating thereto and if at such time any events shall have occurred as a result of which the Prospectus as then amended or supplemented would include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made when such Prospectus is delivered, not misleading, or, if for any other reason it shall be necessary to amend or supplement the Prospectus or to file under the Exchange Act any document incorporated by reference in the Prospectus in order to comply with the Securities Act, the Exchange Act or the Trust Indenture Act, to notify the Representatives in writing and, upon their request, to file such document and to prepare and furnish without charge to each Underwriter and to any dealer in securities as many copies as the Representatives may from time to time reasonably request of an amended or supplemented Prospectus that will correct such statement or omission or effect such compliance;

(iv) To file promptly with the Commission any amendment or supplement to the Registration Statement or the Prospectus that may, in the judgment of the Company, be required by the Securities Act or requested by the Commission, provided, however, that the Company shall consider in good faith any recommendations of the Representatives related thereto;

(v) Prior to filing with the Commission any amendment or supplement to the Registration Statement or the Prospectus, any document incorporated by reference in the Prospectus or any amendment to any document incorporated by reference in the Prospectus, to furnish a copy thereof to the Representatives and counsel for the Underwriters and obtain the written consent (which written consent may be communicated by electronic communication) of the Representatives to the filing (such consent not to be unreasonably delayed or withheld);

(vi) Not to make any offer relating to the Securities that would constitute an Issuer Free Writing Prospectus without the prior written consent (including written consent provided via electronic mail) of the Representatives (such consent not to be unreasonably delayed or withheld);

(vii) To comply with all applicable requirements of Rule 433 of the Rules and Regulations with respect to any Issuer Free Writing Prospectus; and if at any time after the date hereof any events shall have occurred as a result of which any Issuer Free Writing Prospectus, as then amended or supplemented, would conflict with the information in the Registration Statement, the Pricing Disclosure Package or the Prospectus or would include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, or, if for any other reason it shall be necessary to amend or supplement any Issuer Free Writing Prospectus, to notify the Representatives and, upon their reasonable request, to file such document and to prepare and furnish without charge to each Underwriter as many copies as the Representatives may from time to time reasonably request of an amended or supplemented Issuer Free Writing Prospectus that will correct such conflict, statement or omission or effect such compliance;

(viii) As soon as practicable after the Effective Date and in any event not later than 16 months after the date hereof, to make generally available to the Company’s security holders and to deliver to the Representatives an earnings statement of the Company and its subsidiaries (which need not be audited) complying with Section 11(a) of the Securities Act and the Rules and Regulations;

(ix) Promptly from time to time to take such action as the Underwriters may reasonably request to qualify the Securities for offering and sale under the securities or Blue Sky laws of such jurisdictions as the Underwriters may reasonably request, and to maintain such qualifications in effect for as long as may be necessary to complete the distribution of the Securities; provided that in connection therewith the Company shall not be required to (i) qualify as a foreign corporation in any jurisdiction in which it would not otherwise be required to so qualify; (ii) file a general consent to service of process in any such jurisdiction; or (iii) subject itself to taxation in any jurisdiction in which it would not otherwise be subject; and

(x) To apply the net proceeds from the sale of the Securities being sold by the Company as set forth in the Preliminary Prospectus and the Prospectus.

(b) Each Underwriter severally represents and agrees that, unless it obtains the prior written consent (including written consent provided via electronic mail) of the Company and the Representatives, it has not made and will not make any offer relating to the Securities that would constitute an “issuer free writing prospectus,” as defined in Rule 433 of the Rules and Regulations, or that would otherwise constitute a “free writing prospectus,” as defined in Rule 405 of the Rules and Regulations, required to be filed with the Commission.

6. Expenses. The Company will pay and bear all costs and expenses incident to the performance of its obligations under this Agreement, including (i) the preparation, printing and filing of the Registration Statement (including financial statements and any schedules or exhibits and any documents incorporated therein by reference), as originally filed and as amended, the Pricing Disclosure Package and the Prospectus and any amendments or supplements thereto, and the cost of furnishing copies thereof in accordance with Section 5(a)(iii) of this Agreement thereto to the Underwriters; (ii) the preparation, printing and distribution of this Agreement, the Indenture, the Securities, the blue sky survey and the legal investment survey; (iii) the delivery of the Securities to the Underwriters; (iv) the fees and disbursements of the Company’s counsel and accountants; (v) the qualification of the Securities under the applicable securities laws in accordance with Section 5(a)(ix) and any filing for review of the offering with FINRA; (vi) any fees charged by rating agencies for rating the Securities; and (vii) the fees and expenses of the Trustee, including the fees and disbursements of counsel for the Trustee, in connection with the Indenture and the Securities.

7. Conditions of Underwriters’ Obligations. The respective obligations of the Underwriters hereunder are subject to the accuracy, when made and on the date of the Prospectus and on the Closing Date, of the representations and warranties of the Company contained herein, to the performance by the Company of its obligations hereunder, and to each of the following additional terms and conditions:

(a) The Prospectus shall have been timely filed with the Commission in accordance with Section 5(a)(i) and Section 5(a)(iv) hereof; the Company shall have complied with all filing requirements applicable to any Issuer Free Writing Prospectus used or referred to after the date hereof; no stop order suspending the effectiveness of the Registration Statement or preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus shall have been issued and no proceeding or examination for such purpose shall have been initiated or threatened by the Commission; any request of the Commission for inclusion of additional information in the Registration Statement or the Prospectus or any document incorporated by reference therein or otherwise shall have been complied with; and the Commission shall not have notified the Company of any objection to the use of the form of the Registration Statement.

(b) No Underwriter shall have discovered and disclosed to the Company on or prior to the Closing Date that the Registration Statement, the Prospectus or the Pricing Disclosure Package, or any amendment or supplement thereto, contains an untrue statement of a fact which, in the reasonable opinion of ▇▇▇▇▇▇▇ ▇▇▇▇▇ LLP, counsel for the Underwriters, is

material or omits to state a fact which, in the opinion of such counsel, is material and is required to be stated therein or is necessary to make the statements therein not misleading.

(c) All corporate proceedings and other legal matters incident to the authorization, form and validity of this Agreement, the Securities, the Indenture, the Registration Statement, the Prospectus and any Issuer Free Writing Prospectus, and all other legal matters relating to this Agreement and the transactions contemplated hereby shall be reasonably satisfactory in all material respects to counsel for the Underwriters, and the Company shall have furnished to such counsel all documents and information that they may reasonably request to enable them to pass upon such matters.

(d) ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇▇▇ LLP shall have furnished to the Underwriters its written opinion and its separate negative assurance letter, as counsel to the Company, addressed to the Underwriters and delivered and dated the Closing Date, in form and substance reasonably satisfactory to the Underwriters, addressing the matters set forth on Exhibit A attached hereto.

(e) ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇, Assistant General Counsel of the Company, shall have furnished to the Underwriters his written opinion addressed to the Underwriters and delivered and dated the Closing Date, in form and substance reasonably satisfactory to the Underwriters, addressing the matters set forth on Exhibit B attached hereto.

(f) The Representatives shall have received from ▇▇▇▇▇▇▇ ▇▇▇▇▇ LLP, counsel for the Underwriters, such opinion or opinions, dated the Closing Date, with respect to the issuance and sale of the Securities, the Registration Statement, the Prospectus and the Pricing Disclosure Package and other related matters as the Representatives may reasonably require, and the Company shall have furnished to such counsel such documents as they reasonably request for the purpose of enabling them to pass upon such matters.

(g) At the time of execution of this Agreement, the Representatives shall have received from PricewaterhouseCoopers LLP a letter, in form and substance reasonably satisfactory to the Representatives, addressed to the Underwriters and the Company and dated the date hereof (i) confirming that they are independent registered public accountants within the meaning of the Securities Act and are in compliance with the applicable requirements relating to the qualification of accountants under Rule 2-01 of Regulation S-X of the Commission and (ii) stating, as of the date hereof (or, with respect to matters involving changes or developments since the respective dates as of which specified financial information is given in the Preliminary Prospectus, as of a date not more than three days prior to the date hereof), the conclusions and findings of such firm with respect to the financial information and other matters ordinarily covered by accountants’ “comfort letters” to underwriters in connection with registered public offerings.

(h) With respect to the letter of PricewaterhouseCoopers LLP referred to in the preceding paragraph and delivered to the Representatives concurrently with the execution of this Agreement (the “initial letter”), PricewaterhouseCoopers LLP shall have furnished to the Representatives a letter (the “bring-down letter”) of such accountants, addressed to the Underwriters and the Company and dated the Closing Date (i) confirming that they are independent public accountants within the meaning of the Securities Act and are in compliance

with the applicable requirements relating to the qualification of accountants under Rule 2-01 of Regulation S-X of the Commission; (ii) stating, as of the date of the bring-down letter (or, with respect to matters involving changes or developments since the respective dates as of which specified financial information is given in the Prospectus, as of a date not more than three days prior to the date of the bring-down letter), the conclusions and findings of such firm with respect to the financial information and other matters covered by the initial letter; (iii) covering financial information in the Prospectus; and (iv) confirming in all material respects the conclusions and findings set forth in the initial letter.

(i) The Company shall have furnished to the Representatives a certificate, dated the Closing Date, of any vice-president of the Company and the principal financial officer, vice president/treasurer or principal accounting officer of the Company satisfactory to the Representatives to the effect that:

(i) The representations and warranties of the Company in Section 1 that are qualified by materiality or similar qualifiers are true and correct on and as of the Closing Date and the representations and warranties of the Company in Section 1 that are not qualified by materiality or similar qualifiers are true and correct in all material respects on and as of the Closing Date, and the Company has complied in all material respects with all its agreements contained herein and satisfied all the conditions on its part to be performed or satisfied hereunder at or prior to the Closing Date;

(ii) No stop order suspending the effectiveness of the Registration Statement has been issued; no proceedings or examination for that purpose have been instituted or, to the knowledge of such officers, threatened; and the Commission has not notified the Company of any objection to the use of the form of the Registration Statement or any post-effective amendment thereto; and

(iii) They have examined the Registration Statement, the Prospectus and the Pricing Disclosure Package, and, in their opinion, (1) the Registration Statement, as of each Effective Date, (2) the Prospectus, as of its date and as of the Closing Date, and (3) the Pricing Disclosure Package, as of the Applicable Time and as of the Closing Date, did not and do not contain any untrue statement of a material fact and did not and do not omit to state a material fact required to be stated therein or necessary to make the statements therein (except in the case of the Registration Statement, in the light of the circumstances under which they were made) not misleading.

(j) Except as described in the Pricing Disclosure Package and the Prospectus, (i) neither the Company nor any of its subsidiaries shall have sustained, since the date of the latest audited financial statements incorporated by reference in the Pricing Disclosure Package, any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree or (ii) since such date there shall not have been any change in the capital stock (other than Common Stock dividends paid on March 1, June 1 and September 1, 2016); or long-term debt of the Company or any of its subsidiaries or any change, or any development involving a prospective change, in or affecting the condition (financial or otherwise), results of operations, stockholders’ equity, business or properties of the Company and its subsidiaries taken as a

whole, the effect of which, in any such case described in clause (i) or (ii), is, individually or in the aggregate, in the reasonable judgment of the Representatives, so material and adverse as to make it impracticable or inadvisable to proceed with the offering or sale of the Securities being delivered on the Closing Date on the terms and in the manner contemplated in the Pricing Disclosure Package, the Prospectus or this Agreement.

(k) Subsequent to the execution and delivery of this Agreement, (i) no downgrade in the rating of the Company or its financial strength or the rating of any of the Company’s securities by any “nationally recognized statistical rating organization,” as such term is defined in Section 3(a)(62) of the Exchange Act (the “Rating Agencies”) shall have occurred or be pending and (ii) no Rating Agency shall have publicly announced that it has under surveillance or review, with possible negative implications, its rating of the Company or the Company’s financial strength or its rating of any of the Company’s securities.

(l) Subsequent to the execution and delivery of this Agreement there shall not have occurred any of the following: (i) trading in securities generally on the New York Stock Exchange or the NASDAQ National Market, or trading in any securities of the Company on any exchange or in the over-the-counter market, shall have been suspended or materially limited or the settlement of such trading generally shall have been materially disrupted or minimum prices shall have been established on any such exchange or such market by the Commission, by such exchange or by any other regulatory body or governmental authority having jurisdiction; (ii) a general moratorium on commercial banking activities shall have been declared by federal or New York state authorities; or (iii) the United States shall have become engaged in hostilities, there shall have been an escalation in hostilities involving the United States, there shall have been a declaration of a national emergency or war by the United States, there shall have occurred such a material adverse change in general economic, political or financial conditions, including, without limitation, as a result of terrorist activities after the date hereof (or the effect of international conditions on the financial markets in the United States shall be such), as to make it, in the judgment of the Representatives, impracticable or inadvisable to proceed with the offering or sale of the Securities being delivered on the Closing Date on the terms and in the manner contemplated in the Pricing Disclosure Package, the Prospectus or this Agreement.

All opinions, letters, evidence and certificates mentioned above or elsewhere in this Agreement shall be deemed to be in compliance with the provisions hereof only if they are in form and substance reasonably satisfactory to counsel for the Underwriters.

8. Indemnification and Contribution.

(a) The Company shall indemnify and hold harmless each Underwriter, its affiliates, directors, officers, members and employees and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Securities Act, from and against any loss, claim, damage or liability, joint or several, or any action in respect thereof (including, but not limited to, any loss, claim, damage, liability or action relating to purchases and sales of Securities), to which such Underwriter or such affiliate, director, officer, member, employee or controlling person may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, liability or action arises out of, or is based upon, (i) any untrue statement or alleged untrue statement of a material fact contained in (A) the Preliminary Prospectus, the

Registration Statement, the Prospectus or in any amendment or supplement thereto, (B) any Issuer Free Writing Prospectus or in any amendment or supplement thereto or (C) any “issuer information” (as defined in Rule 433 of the Rules and Regulations) used or referred to in any “free writing prospectus” (as defined in Rule 405 of the Rules and Regulations) used or referred to by any Underwriter (“Permitted Issuer Information”) or (ii) the omission or alleged omission to state in the Preliminary Prospectus, the Registration Statement, the Prospectus, any Issuer Free Writing Prospectus or in any amendment or supplement thereto or in any Permitted Issuer Information, any material fact required to be stated therein or necessary to make the statements therein, (except in the case of the Registration Statement) in the light of the circumstances under which they were made, not misleading, and shall reimburse each Underwriter and each such director, officer, employee or controlling person promptly upon demand for any legal or other expenses reasonably incurred by the Underwriter or such affiliate, director, officer, employee or controlling person in connection with investigating or defending or preparing to defend against any such loss, claim, damage, liability or action as such expenses are incurred; provided, however, that the Company shall not be liable in any such case to the extent that any such loss, claim, damage, liability or action arises out of, or is based upon, any untrue statement or alleged untrue statement or omission or alleged omission made in the Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus, or in any amendment or supplement thereto, in reliance upon and in conformity with written information concerning such Underwriter furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information consists solely of the information specified in Section 8(e) hereof. The foregoing indemnity agreement is in addition to any liability which the Company may otherwise have to any Underwriter or to any affiliate, director, officer, member, employee or controlling person of that Underwriter.

(b) Each Underwriter, severally and not jointly, shall indemnify and hold harmless the Company, its directors, officers and employees, and each person, if any, who controls the Company within the meaning of Section 15 of the Securities Act, from and against any loss, claim, damage or liability, joint or several, or any action in respect thereof, to which the Company or any such director, officer, employee or controlling person may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, liability or action arises out of, or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus, or in any amendment or supplement thereto, or (ii) the omission or alleged omission to state in the Preliminary Prospectus, the Prospectus or any Issuer Free Writing Prospectus, or in any amendment or supplement thereto, any material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, but in each case only to the extent that the untrue statement or alleged untrue statement or omission or alleged omission was made in reliance upon and in conformity with written information concerning such Underwriter furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information consists solely of the information specified in Section 8(e) hereof, and shall reimburse the Company, each of its directors, officers, employees or controlling persons promptly upon demand for any legal or other expenses reasonably incurred by the Company or such director, officer, employee or controlling person in connection with investigating or defending or preparing to defend against any such loss, claim, damage, liability or action as such expenses are incurred. The foregoing indemnity agreement is in addition to any liability that any

Underwriter may otherwise have to the Company or any such director, officer, employee or controlling person of the Company.

(c) Promptly after receipt by an indemnified party under this Section 8 of notice of any claim or the commencement of any action, the indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under this Section 8, notify the indemnifying party in writing of the claim or the commencement of that action; provided, however, that the failure to notify the indemnifying party shall not relieve it from any liability which it may have under this Section 8 except to the extent it has been materially prejudiced by such failure and, provided, further, that the failure to notify the indemnifying party shall not relieve it from any liability which it may have to an indemnified party otherwise than under this Section 8. If any such claim or action shall be brought against an indemnified party, and it shall notify the indemnifying party thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it wishes, jointly with any other similarly notified indemnifying party, to assume the defense thereof with one counsel reasonably satisfactory to the indemnified party. After notice from the indemnifying party to the indemnified party of its election to assume the defense of such claim or action, the indemnifying party shall not be liable to the indemnified party under this Section 8 for any legal or other expenses subsequently incurred by the indemnified party in connection with the defense thereof other than reasonable costs of investigation; provided, however, that the indemnified parties, jointly, shall have the right to employ one counsel to represent jointly the indemnified party and those other indemnified parties and their respective directors, officers, members, employees and controlling persons who may be subject to liability arising out of any claim in respect of which indemnity may be sought under this Section 8 if (i) the indemnified party and the indemnifying party shall have so mutually agreed; (ii) the indemnifying party has failed within a reasonable time to retain counsel reasonably satisfactory to the indemnified party; (iii) the indemnified party and its directors, officers, members, employees and controlling persons shall have reasonably concluded that there may be legal defenses available to them that are different from or in addition to those available to the indemnifying party; or (iv) the named parties in any such proceeding (including any impleaded parties) include both the indemnified parties or their respective directors, officers, members, employees or controlling persons, on the one hand, and the indemnifying party, on the other hand, and representation of both sets of parties by the same counsel would be inappropriate due to actual or potential differing interests between them, and in any such event the fees and expenses of such separate counsel shall be paid by the indemnifying party as incurred. No indemnifying party shall (i) without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of any judgment with respect to any pending or threatened claim, action, suit or proceeding in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified parties are actual or potential parties to such claim or action) unless such settlement, compromise or consent includes an unconditional release of each indemnified party from all liability arising out of such claim, action, suit or proceeding and does not include any findings of fact or admissions of fault or culpability as to the indemnified party or (ii) be liable for any settlement of any such action effected without its written consent (which consent shall not be unreasonably withheld), but if settled with the consent of the indemnifying party or if there be a final judgment for the plaintiff in any such action, the indemnifying party agrees to indemnify and hold harmless any indemnified party from and against any loss or liability by reason of such settlement or judgment.

(d) If the indemnification provided for in this Section 8 shall for any reason be unavailable to or insufficient to hold harmless an indemnified party under Section 8(a) or 8(b) hereof in respect of any loss, claim, damage or liability, or any action in respect thereof, referred to therein, then each indemnifying party shall, in lieu of indemnifying such indemnified party, contribute to the amount paid or payable by such indemnified party as a result of such loss, claim, damage or liability, or action in respect thereof, (i) in such proportion as shall be appropriate to reflect the relative benefits received by the Company, on the one hand, and the Underwriters, on the other, from the offering of the Securities or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company, on the one hand, and the Underwriters, on the other, with respect to the statements or omissions that resulted in such loss, claim, damage or liability, or action in respect thereof, as well as any other relevant equitable considerations. The relative benefits received by the Company, on the one hand, and the Underwriters, on the other, with respect to such offering shall be deemed to be in the same proportion as the total net proceeds from the offering of the Securities purchased under this Agreement (before deducting expenses) received by the Company, as set forth in the table on the cover page of the Prospectus, on the one hand, and the total underwriting discounts and commissions received by the Underwriters with respect to the principal amount of Securities purchased under this Agreement, as set forth in the table on the cover page of the Prospectus, on the other hand. The relative fault of the Company, on the one hand, and the Underwriters, on the other, shall be determined by reference to whether the untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company or the Underwriters, the intent of the parties and their relative knowledge, access to information and opportunity to correct or prevent such statement or omission. The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 8(d) were to be determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take into account the equitable considerations referred to herein. The amount paid or payable by an indemnified party as a result of the loss, claim, damage or liability, or action in respect thereof, referred to above in this Section 8(d) shall be deemed to include, for purposes of this Section 8(d), any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 8(d), no Underwriter shall be required to contribute any amount in excess of the amount by which the net proceeds from the sale of the Securities underwritten by it exceeds the amount of any damages that such Underwriter has otherwise paid or become liable to pay by reason of any untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute as provided in this Section 8(d) are several in proportion to their respective underwriting obligations and not joint.

(e) The Underwriters severally confirm, and the Company acknowledges and agrees, that the statements set forth in the first and second sentences in the first paragraph under the caption “Underwriting—Commissions and Discounts,” the third and fourth sentences in the first paragraph under the caption “Underwriting—New Issue of Notes” and the first and second paragraphs under the caption “Underwriting—Short Positions” in the Preliminary Prospectus and

the Prospectus are correct and constitute the only information concerning such Underwriters furnished in writing to the Company by or on behalf of the Underwriters specifically for inclusion in the Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus, or any amendment or supplement thereto.

9. Termination.

(a) The obligations of the Underwriters hereunder may be terminated by the Representatives by written notice given to and received by the Company prior to delivery of and payment for the Securities if, prior to that time, any of the events described in Sections 7(j), 7(k) and 7(l) hereof shall have occurred, or if the Underwriters shall decline to purchase the Securities for any reason permitted under this Agreement.

(b) If this Agreement is terminated by the Representatives in accordance with the provisions of Section 7 or Section 10, the Company shall, subject to the limitations set forth in Section 11, reimburse the Underwriters for all their out-of-pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriters.

10. Default of One or More of the Several Underwriters. If, on the Closing Date any one or more of the several Underwriters shall fail or refuse to purchase Securities that it or they have agreed to purchase hereunder on such date, and the aggregate principal amount which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase does not exceed 10% of the aggregate principal amount of the Securities to be purchased on such date, the other Underwriters shall be obligated, severally, in the proportions that the principal amount of Securities set forth opposite their respective names on Schedule 1 bears to the aggregate principal amount of Securities set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as may be specified by the Representatives with the consent of the non-defaulting Underwriters, to purchase the Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date. If, on the Closing Date, any one or more of the Underwriters shall fail or refuse to purchase Securities and the aggregate principal amount of Securities with respect to which such default occurs exceeds 10% of the aggregate principal amount of Securities to be purchased on such date, and arrangements satisfactory to the Representatives and the Company for the purchase of such Securities are not made within 48 hours after such default, this Agreement shall terminate without liability of any party to any other party except that the provisions of Section 6, Section 8, and Section 11 hereof shall at all times be effective and shall survive such termination. In any such case either the Representatives or the Company shall have the right to postpone the Closing Date, but in no event for longer than seven days in order that the required changes, if any, to the Registration Statement and the Prospectus or any other documents or arrangements may be effected.

As used in this Agreement, the term “Underwriter” shall be deemed to include any person substituted for a defaulting Underwriter under this Section 10. Any action taken under this Section 10 shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

11. Reimbursement of Underwriters’ Expenses. If (a) the Company shall fail to tender the Securities for delivery to the Underwriters by reason of any failure, refusal or inability on the part of the Company to perform any agreement to be performed on its part hereunder, or because any other condition of the obligations hereunder required to be fulfilled by the Company is not fulfilled for any reason, or (b) the Underwriters shall decline to purchase the Securities for any reason permitted under this Agreement, the Company will reimburse the Underwriters for all reasonable out-of-pocket expenses (including reasonable fees and disbursements of one counsel) not to exceed $250,000 incurred by the Underwriters in connection with this Agreement and the proposed purchase of the Securities and upon demand the Company shall pay the full amount thereof to the Representatives; provided, however, that in no event shall the Company be obligated to reimburse the out-of-pocket expenses of any defaulting Underwriter referred to in Section 10 hereof or any Underwriter found to be in breach of this Agreement as of the Applicable Time.

12. Research Analyst Independence. The Company acknowledges that the Underwriters’ research analysts and research departments are required to be independent from their respective investment banking divisions and are subject to certain regulations and internal policies, and that such Underwriters’ research analysts may hold views and make statements or investment recommendations and/or publish research reports with respect to the Company and/or the offering that differ from the views of their respective investment banking divisions. The Company hereby waives and releases, to the fullest extent permitted by law, any claims that the Company may have against the Underwriters with respect to any conflict of interest that may arise from the fact that the views expressed by their independent research analysts and research departments may be different from or inconsistent with the views or advice communicated to the Company by such Underwriters’ investment banking divisions. The Company acknowledges that each of the Underwriters is a full service securities firm and as such from time to time, subject to applicable securities laws, may effect transactions for its own account or the account of its customers and hold long or short positions in debt or equity securities of the Company.

13. No Fiduciary Duty. The Company acknowledges and agrees that in connection with this offering, sale of the Securities or any other services the Underwriters may be deemed to be providing hereunder, notwithstanding any preexisting relationship, advisory or otherwise, between the parties or any oral representations or assurances previously or subsequently made by the Underwriters: (i) no fiduciary or agency relationship between the Company and any other person, on the one hand, and the Underwriters, on the other, exists; (ii) the Underwriters are not acting as advisors, expert or otherwise, to the Company, including, without limitation, with respect to the determination of the public offering price of the Securities, and such relationship between the Company, on the one hand, and the Underwriters, on the other, is entirely and solely commercial, based on arms-length negotiations; (iii) any duties and obligations that the Underwriters may have to the Company shall be limited to those duties and obligations specifically stated herein; and (iv) the Underwriters and their respective affiliates may have interests that differ from those of the Company. The Company hereby waives any claims that the Company may have against the Underwriters with respect to any breach of fiduciary duty in connection with this offering. Any review by the Underwriters of the Company, the transactions contemplated hereby or other matters relating to such transactions will be performed solely for the benefit of the Underwriters and shall not be on behalf of the Company.

14. Notices, Etc. All statements, requests, notices and agreements hereunder shall be in writing, and:

(a) if to the Underwriters, shall be delivered or sent by mail to BNY Mellon Capital Markets, LLC, ▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Attention: Debt Capital Markets; ▇.▇. ▇▇▇▇▇▇ Securities LLC, ▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Facsimile: (▇▇▇) ▇▇▇-▇▇▇▇, Attention: Investment Grade Syndicate Desk – 3^rd floor; ▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated, ▇▇ ▇▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇-▇▇▇-▇▇-▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Facsimile: (▇▇▇) ▇▇▇-▇▇▇▇, Attention: High Grade Transaction Management/Legal; and ▇▇▇▇▇ Fargo Securities, LLC, ▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇^▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇, Facsimile: (▇▇▇) ▇▇▇-▇▇▇▇, Attention: Transaction Management; and

(b) if to the Company, shall be delivered or sent by mail or facsimile transmission to Southwest Gas Corporation, ▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇, ▇.▇. ▇▇▇ ▇▇▇▇▇, ▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇ ▇▇▇▇▇, Attention: Treasurer, with a copy (which shall not constitute notice) to ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇, Esq., ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇▇▇ LLP, ▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇.

Any such statements, requests, notices or agreements shall take effect at the time of receipt thereof. The Company shall be entitled to act and rely upon any request, consent, notice or agreement given or made on behalf of the Underwriters by the Representatives.

15. Persons Entitled to Benefit of Agreement. This Agreement shall inure to the benefit of and be binding upon the Underwriters, the Company, and their respective successors. This Agreement and the terms and provisions hereof are for the sole benefit of only those persons, except that (A) the representations, warranties, indemnities and agreements of the Company contained in this Agreement shall also be deemed to be for the benefit of the directors, officers, members and employees of the Underwriters and each person or persons, if any, who control any Underwriter within the meaning of Section 15 of the Securities Act and (B) the indemnity agreement of the Underwriters contained in Section 8(b) hereof shall be deemed to be for the benefit of the directors of the Company, the officers of the Company who have signed the Registration Statement and any person controlling the Company within the meaning of Section 15 of the Securities Act. Nothing in this Agreement is intended or shall be construed to give any person, other than the persons referred to in this Section 15, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision contained herein.

16. Survival. The respective indemnities, representations, warranties and agreements of the Company and the Underwriters contained in this Agreement or made by or on behalf of them, respectively, pursuant to this Agreement, shall survive the delivery of and payment for the Securities and shall remain in full force and effect, regardless of any investigation made by or on behalf of any of them or any person controlling any of them.

17. Definition of the Terms “Business Day” and “Subsidiary.” For purposes of this Agreement, (a) “business day” means each Monday, Tuesday, Wednesday, Thursday or Friday that is not a day on which banking institutions in New York are generally authorized or

obligated by law or executive order to close and (b) “subsidiary” has the meaning set forth in Rule 405 of the Rules and Regulations.

18. Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of New York, without regard to the conflicts of laws rules of such state.

19. Waiver of Jury Trial. THE COMPANY AND THE UNDERWRITERS HEREBY WAIVE ALL RIGHT TO TRIAL BY JURY IN ANY PROCEEDING (WHETHER BASED UPON CONTRACT, TORT OR OTHERWISE) IN ANY WAY ARISING OUT OF OR RELATING TO THIS AGREEMENT. The Company and the Underwriters agree that a final judgment in any such proceeding brought in any court shall be conclusive and binding upon the Company and the Underwriters, as applicable, and may be enforced in any other courts in the jurisdiction of which the Company or the Underwriters are or may be subject, by suit upon such judgment.

20. Counterparts. This Agreement may be executed in one or more counterparts and, if executed in more than one counterpart, the executed counterparts shall each be deemed to be an original but all such counterparts shall together constitute one and the same instrument.

21. Headings. The headings herein are inserted for convenience of reference only and are not intended to be part of, or to affect the meaning or interpretation of, this Agreement.

[Signature page follows]

If the foregoing correctly sets forth the agreement between the Company and the Underwriters, please indicate your acceptance in the space provided for that purpose below.


Very truly yours,

SOUTHWEST GAS CORPORATION

By:		/s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
		Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇ Title: Vice President/Finance/Treasurer

Accepted:


BNY MELLON CAPITAL MARKETS, LLC

By:		/s/ ▇▇▇ ▇▇▇▇▇▇▇
		Name: ▇▇▇ ▇▇▇▇▇▇▇ Title: Managing Director

▇.▇. ▇▇▇▇▇▇ SECURITIES LLC

By:		/s/ Som ▇▇▇▇▇▇▇▇▇▇▇▇▇
		Name: Som ▇▇▇▇▇▇▇▇▇▇▇▇▇ Title: Vice President

▇▇▇▇▇▇▇ LYNCH, PIERCE, ▇▇▇▇▇▇ & ▇▇▇▇▇ INCORPORATED

By:		/s/ ▇▇▇▇▇ ▇▇▇▇▇▇
		Name: ▇▇▇▇▇ ▇▇▇▇▇▇ Title: Managing Director

▇▇▇▇▇ FARGO SECURITIES, LLC

By:		/s/ ▇▇▇▇ ▇▇▇▇▇▇▇▇
		Name: ▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: Managing Director

For themselves and as Representatives of the Underwriters named in Schedule 1 hereto

Signature Page

SCHEDULE 1


Underwriters	Principal Amount of Notes
BNY Mellon Capital Markets, LLC	$	60,000,000
▇.▇. ▇▇▇▇▇▇ Securities LLC		60,000,000
▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated		60,000,000
▇▇▇▇▇ Fargo Securities, LLC		60,000,000
▇▇▇▇▇▇▇▇ ▇▇▇▇ Van, LLC		30,000,000
▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇ & Company, Inc.		30,000,000
Total	$	300,000,000

SCHEDULE 2

PRICING INFORMATION


Issuer:		Southwest Gas Corporation

Title of Securities:		3.80% Senior Notes due 2046

Security Type:		Senior Unsecured Fixed Rate Notes

Ratings¹:		A3 (stable) by ▇▇▇▇▇’▇ Investors Service, Inc. BBB+ (stable) by Standard & Poor’s Ratings Services A (stable) by Fitch Ratings Ltd.

Format:		Registered with the Securities and Exchange Commission

Trade Date:		September 26, 2016

Settlement Date (T+3):		September 29, 2016

Maturity Date:		September 29, 2046

Aggregate Principal Amount Offered:		$300,000,000

Net Proceeds:		$296,469,000 (after underwriting discount and before an estimated $600,000 of offering expenses)

Benchmark Treasury:		2.500% due May 15, 2046

Benchmark Treasury Yield:		2.317%

Spread to Benchmark:		T+150 basis points

Re-offer Yield:		3.817%

Coupon:		3.80% per annum

Price to the Public (Issue Price):		99.698%

Interest Payment Dates:		Semi-annually on April 1 and October 1 of each year, beginning on April 1, 2017

Redemption Provisions:		At any time prior to March 29, 2046, at a discount rate of Treasury rate plus 25 basis points; and on or after March 29, 2046, 100% of the principal amount plus accrued and unpaid interest to the redemption date

CUSIP / ISIN:		844895 AX0 / US844895AX00



Minimum Denomination:		$2,000, and integral multiples of $1,000 in excess thereof

Joint Book-Running Managers:		BNY Mellon Capital Markets, LLC ▇.▇. ▇▇▇▇▇▇ Securities LLC ▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated ▇▇▇▇▇ Fargo Securities, LLC

Co-Managers:		▇▇▇▇▇▇▇▇ ▇▇▇▇ Van, LLC ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇ & Company, Inc.

An explanation of the significance of ratings may be obtained from the rating agencies. Generally, rating agencies base their ratings on such material and information, and such of their own investigations, studies and assumptions, as they deem appropriate. The ratings of the Notes should be evaluated independently from similar ratings of other securities. A credit rating of a security is not a recommendation to buy, sell or hold securities and may be subject to review, revision, suspension, reduction or withdrawal at any time by the assigning rating agency.

SCHEDULE 3

LIST OF SIGNIFICANT SUBSIDIARIES


Subsidiary Name		State of Incorporation or Organization Type
Paiute Pipeline Company		Nevada
NPL Construction Co.		Nevada
NPL Canada LTD.		Ontario, Canada

SCHEDULE 4

LIST OF SUBSIDIARIES


Subsidiary Name		State of Incorporation or Organization Type
Paiute Pipeline Company		Nevada
NPL Construction Co.		Nevada
Southwest Administrators, Inc.		Nevada
IntelliChoice Energy LLC		Delaware
IntelliChoice Energy of California LLC		Delaware
Southwest Gas Transmission Company		Arizona Limited Partnership between Southwest Gas Corporation and Utility Financial Corp.
Southwest Gas Capital III		Delaware
Southwest Gas Capital IV		Delaware
Utility Financial Corp.		Nevada
The Southwest Companies		Nevada
▇▇▇▇▇▇ Water Company		Nevada
Centuri Construction Group, Inc.		Nevada
Vistus Construction Group, Inc.		Nevada
Brigadier Pipelines, Inc.		Nevada
Canyon Pipeline Construction, Inc.		Nevada
Lynxus Construction Group Inc.		Ontario, Canada
NPL Canada LTD.		Ontario, Canada
Ontario LTD.		Ontario, Canada
▇.▇. ▇▇▇▇▇▇▇▇ Construction Inc.		Ontario, Canada
▇.▇. ▇▇▇▇▇▇▇▇ Industries Inc.		Ontario, Canada

SOUTHWEST GAS CORPORATION $300,000,000 3.80% Senior Notes due 2046 UNDERWRITING AGREEMENT

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