REGISTRATION RIGHTS AGREEMENT by and among LyondellBasell Industries N.V. and the Holders (as defined herein) Dated as of April 30, 2010

Exhibit 4.3

REGISTRATION RIGHTS AGREEMENT

by and among

LyondellBasell Industries N.V.

and

the Holders (as defined herein)

Dated as of April 30, 2010

REGISTRATION RIGHTS AGREEMENT

     This Registration Rights Agreement (this “Agreement”) is made as of April 30, 2010 by and among LyondellBasell Industries N.V., a public limited liability company (naamloze vennootschap) formed under the laws of The Netherlands (the “Parent Guarantor”), Lyondell Chemical Company, a Delaware corporation (the “Company”), the Subsidiary Guarantors identified on the signature pages hereto and the Holders (as defined below). Capitalized terms used but not otherwise defined herein are defined in Section 1 hereof.

     This Agreement is made pursuant to the Plan of Reorganization (as defined below) and the Indenture (as defined below) relating to the 11% Senior Secured Notes due 2018 (the “Notes”), for the benefit of the Holders from time to time. The Notes are fully and unconditionally guaranteed (the “Guarantees”) by the Parent Guarantor and the Subsidiary Guarantors (collectively, the “Guarantors”) pursuant to the Indenture. The Notes and the Guarantees attached thereto are herein collectively referred to as the “Securities.”

     The parties hereby agree as follows:

     SECTION 1. Definitions. As used in this Agreement, the following capitalized terms shall have the following meanings:

     8% Notes: The 8% Senior Secured Notes due 2017 issued by LBI Escrow Corporation on April 8, 2010, to be assumed by the Company and guaranteed by the Guarantors on the date of this Agreement.

     8% Notes Registration Rights Agreement: The Registration Rights Agreement dated as of April 8, 2010 by and among LBI Escrow Corporation, the Parent Guarantor and the initial purchasers named therein, as amended on the date of this Agreement.

     Business Day: Any day other than a Saturday, Sunday or other day on which banking institutions or trust companies are authorized or required by law to close in New York City, London or The Netherlands.

     Commission: The United States Securities and Exchange Commission.

     Effectiveness Target Date: The date that is the earlier of (1) 365 days after the date of this Agreement or if such 365th day is not a Business Day, the next succeeding Business Day and (2) the date that the Exchange Offer Registration Statement required by the 8% Notes Registration Rights Agreement is declared effective by the Commission.

     Exchange Act: The Securities Exchange Act of 1934, as amended.

     Exchange Offer: The registration by the Company under the Securities Act of the offer to exchange the 8% Notes for a like principal amount of similar notes that have been registered under the Securities Act, which offer to exchange is required to be made pursuant to the 8% Notes Registration Rights Agreement.

     Exchange Offer Registration Statement: The Registration Statement relating to the Exchange Offer, including the related Prospectus.

     FINRA: Financial Industry Regulatory Authority, Inc.

     Holders: As defined in Section 2(b) hereof.

     Indemnified Holder: As defined in Section 7(a) hereof.

     Indenture: The Indenture, dated as of April 30, 2010, by and among the Company, the Guarantors and ▇▇▇▇▇ Fargo Bank, N.A., as trustee and collateral agent, pursuant to which the Securities are to be issued, as such Indenture is amended or supplemented from time to time in accordance with the terms thereof.

     Initial Placement: The issuance by the Company of the Securities to the Holders pursuant to the Plan of Reorganization.

     Notes: As defined in the preamble hereto.

     Person: An individual, partnership, corporation, trust or unincorporated organization, or a government or agency or political subdivision thereof.

     Plan of Reorganization: The Plan of Reorganization of LyondellBasell Industries AF S.C.A. and certain of its subsidiaries and affiliates under chapter 11, title 11 of the United States Code, 11 U.S.C. §§101-1532.

     Prospectus: The prospectus included in a Registration Statement, as amended or supplemented by any prospectus supplement and by all other amendments thereto, including post-effective amendments, and all material incorporated by reference into such Prospectus.

     Registration Default: As defined in Section 4 hereof.

     Registration Statement: Any registration statement of the Company relating to the registration for resale of Transfer Restricted Securities pursuant to the Shelf Registration Statement, which is filed pursuant to the provisions of this Agreement, in each case, including the Prospectus included therein, all amendments and supplements thereto (including post-effective amendments) and all exhibits and material incorporated by reference therein.

     Securities: As defined in the preamble hereto.

     Securities Act: The Securities Act of 1933, as amended.

     Shelf Filing Deadline: As defined in Section 3(a) hereof.

     Shelf Registration Statement: As defined in Section 3(a) hereof.

     Transfer Restricted Securities: Each Security owned by a Holder, until the earliest to occur of (a) the date on which such Security has been effectively registered under the Securities Act and disposed of in accordance with a Shelf Registration Statement pursuant to this Agreement,

(b) the date on which such securities are disposed of pursuant to Rule 144 (or any successor rule then in effect) promulgated under the Securities Act and (c) the date on which such Securities cease to be outstanding and have been cancelled by the Trustee pursuant to the terms of the Indenture.

     Trust Indenture Act: The Trust Indenture Act of 1939, as amended.

     Underwritten Registration or Underwritten Offering: A registration in which Transfer Restricted Securities are sold to an underwriter for reoffering to the public.

     SECTION 2. Securities Subject to this Agreement.

     (a) Transfer Restricted Securities. The securities entitled to the benefits of this Agreement are the Transfer Restricted Securities.

     (b) Holders of Transfer Restricted Securities. A Person is deemed to be a holder of Transfer Restricted Securities (each, a “Holder”) whenever such Person owns Transfer Restricted Securities. Each Holder on the date of this Agreement is identified as such on the signature pages hereto.

     SECTION 3. Shelf Registration.

     (a) Unless there are no Transfer Restricted Securities outstanding, each of the Company and the Guarantors shall (i) use its commercially reasonable efforts to cause to be filed with the Commission as soon as reasonably practicable but in any event no later than the Effectiveness Target Date, a shelf registration statement pursuant to Rule 415 under the Securities Act (the “Shelf Registration Statement”), which Shelf Registration Statement shall provide for resales of all Transfer Restricted Securities the Holders of which shall have provided the information required pursuant to Section 3(c) hereof, (ii) use their commercially reasonable efforts to cause such Shelf Registration Statement to be declared effective by the Commission as soon as reasonably practicable but in any event no later than the Effectiveness Target Date and (iii) in connection with the foregoing, file (A) all pre-effective amendments to such Shelf Registration Statement as may be necessary in order to cause such Shelf Registration Statement to become effective, (B) if applicable, a post-effective amendment to such Registration Statement pursuant to Rule 430A under the Securities Act and (C) cause all necessary filings in connection with the registration and qualification for resale of the Transfer Restricted Securities to be made under the state securities or blue sky laws of such jurisdictions as are necessary. The Shelf Registration Statement shall be on the appropriate form permitting resales of Transfer Restricted Securities held by the Holders as contemplated by this Agreement.

     (b) Each of the Company and the Guarantors shall use its commercially reasonable efforts to keep such Shelf Registration Statement continuously effective, supplemented and amended as required by the provisions of Sections 5(a) and (b) hereof to the extent necessary to ensure that it is available for resales of Securities by the Holders of Transfer Restricted Securities entitled to the benefit of this Section 3, and to ensure that it conforms with the requirements of this Agreement, the Securities Act and the policies, rules and regulations of the Commission as announced from time to time, for a period ending on the earlier of (i) the date when all the Transfer Restricted Securities covered by such Shelf Registration Statement have been sold pursuant

to such Shelf Registration Statement and (ii) the date when there are no Transfer Restricted outstanding (the “Shelf Registration Period”).

     (c) No Holder of Transfer Restricted Securities may include any of its Transfer Restricted Securities in any Shelf Registration Statement pursuant to this Agreement unless and until such Holder furnishes to the Company in writing, within 20 Business Days after receipt of a request therefor, such information as the Company may reasonably request for use in connection with any Shelf Registration Statement or Prospectus or preliminary Prospectus included therein. Each Holder as to which any Shelf Registration Statement is being effected agrees to furnish promptly to the Company all information required to be disclosed in order to make the information previously furnished to the Company by such Holder not to contain an untrue statement of material fact or omit to state any fact necessary to make the statement therein not misleading.

     SECTION 4. Additional Interest. If the Shelf Registration Statement (x) does not become effective on or prior to the Effectiveness Target Date, or (y) becomes effective but thereafter ceases to be effective or the corresponding Prospectus fails to be usable for its intended purpose at any time during the Shelf Registration Period, and such failure to remain effective or usable exists for more than 60 days (whether or not consecutive) in any 12-month period (each such event referred to in the foregoing clauses (x) or (y) a “Registration Default”), the Company hereby agrees that the interest rate borne by the Transfer Restricted Securities shall be increased by 0.25% per annum during the 90-day period immediately following the occurrence of any Registration Default and shall increase by 0.25% per annum at the end of each subsequent 90-day period, but in no event shall such increase exceed 1.00% per annum. Following the earliest of (x) the cure of all Registration Defaults relating to any particular Transfer Restricted Securities, (y) the date on which there are no outstanding Transfer Restricted Securities and (z) the date that is two and one half years after the Release Date, the interest rate borne by the relevant Transfer Restricted Securities will be reduced to the original interest rate borne by such Transfer Restricted Securities; provided, however, that, if after any such reduction in interest rate, a different Registration Default occurs, the interest rate borne by the relevant Transfer Restricted Securities shall again be increased pursuant to the foregoing provisions.

     Notwithstanding the foregoing, the amount of Additional Interest payable shall not increase because more than one Registration Default has occurred and is pending.

     All obligations of the Company and the Guarantors set forth in the preceding paragraph that are outstanding with respect to any Transfer Restricted Security at the time such security ceases to be a Transfer Restricted Security shall survive until such time as all such obligations with respect to such security shall have been satisfied in full.

     SECTION 5. Registration Procedures.

     (a) Shelf Registration Statement. In connection with the Shelf Registration Statement, each of the Company and the Guarantors shall comply with all the provisions of Section 5(b) hereof and shall use its commercially reasonable efforts to effect such registration (unless automatically declared effective) to permit the sale of the Transfer Restricted Securities being sold in accordance with the intended method or methods of distribution thereof, and pursuant thereto each of the Company and the Guarantors will as soon as commercially reasonable prepare

and file with the Commission a Registration Statement relating to the registration on any appropriate form under the Securities Act, which form shall be available for the sale of the Transfer Restricted Securities in accordance with the intended method or methods of distribution thereof.

     (b) General Provisions. In connection with any Registration Statement and any Prospectus required by this Agreement to permit the sale or resale of Transfer Restricted Securities, each of the Company and the Guarantors shall:

     (i) use its commercially reasonable efforts to keep such Registration Statement continuously effective during the period of this Agreement and provide all requisite financial statements (including, if required by the Securities Act or any regulation thereunder, financial statements of the Guarantors for the period specified in Section 3 hereof; upon the occurrence of any event that would cause any such Registration Statement or the Prospectus contained therein (A) to contain a material misstatement or omission or (B) not to be effective and usable for resale of Transfer Restricted Securities during the period required by this Agreement, the Company shall file promptly an appropriate amendment to such Registration Statement, in the case of clause (A), correcting any such misstatement or omission, and, in the case of either clause (A) or (B), use its commercially reasonable efforts to cause such amendment to be declared effective (unless automatically declared effective) and such Registration Statement and the related Prospectus to become usable for their intended purpose(s) as soon as practicable thereafter;

     (ii) prepare and file with the Commission such amendments and post-effective amendments to the applicable Registration Statement as may be necessary to keep the Registration Statement effective for the applicable period set forth in Section 3 hereof, or such shorter period as will terminate when all Transfer Restricted Securities covered by such Registration Statement have been sold; cause the Prospectus to be supplemented by any required Prospectus supplement, and as so supplemented to be filed pursuant to Rule 424 under the Securities Act, and to comply fully with the applicable provisions of Rules 424 and 430A under the Securities Act in a timely manner; and comply with the provisions of the Securities Act with respect to the disposition of all securities covered by such Registration Statement during the applicable period in accordance with the intended method or methods of distribution by the sellers thereof set forth in such Registration Statement or supplement to the Prospectus;

     (iii) advise the underwriter(s), if any, and selling Holders promptly and, if requested by such Persons, to confirm such advice in writing, (A) when the Prospectus or any Prospectus supplement or post-effective amendment has been filed, and, with respect to any Registration Statement or any post-effective amendment thereto, when the same has become effective, (B) of any request by the Commission for amendments to the Registration Statement or amendments or supplements to the Prospectus or for additional information relating thereto, (C) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement under the Securities Act or of the suspension by any state securities commission of the qualification of the Transfer Restricted Securities for offering or sale in any jurisdiction, or the initiation of any proceeding for any of the preceding purposes, (D) of the existence of any fact or the happening of

any event that makes any statement of a material fact made in the Registration Statement, the Prospectus, any amendment or supplement thereto, or any document incorporated by reference therein untrue, or that requires the making of any additions to or changes in the Registration Statement or the Prospectus in order to make the statements therein not misleading. If at any time the Commission shall issue any stop order suspending the effectiveness of the Registration Statement, or any state securities commission or other regulatory authority shall issue an order suspending the qualification or exemption from qualification of the Transfer Restricted Securities under state securities or blue sky laws, each of the Company and the Guarantors shall use its commercially reasonable efforts to obtain the withdrawal or lifting of such order at the earliest possible time;

     (iv) furnish without charge to each selling Holder named in any Registration Statement, and each of the underwriter(s), if any, before filing with the Commission, copies of any Registration Statement or any Prospectus included therein or any amendments or supplements to any such Registration Statement or Prospectus (including all documents incorporated by reference after the initial filing of such Registration Statement), which documents will be subject to the review and comment of such Holders and underwriter(s) in connection with such sale, if any, for a period of at least five Business Days, and the Company will not file any such Registration Statement or Prospectus or any amendment or supplement to any such Registration Statement or Prospectus (including all such documents incorporated by reference) to which a Holder of Transfer Restricted Securities covered by such Registration Statement or the underwriter(s), if any, shall reasonably object in writing within five Business Days after the receipt thereof (such objection to be deemed timely made upon confirmation of telecopy transmission within such period). The objection of a Holder or underwriter, if any, shall be deemed to be reasonable if such Registration Statement, amendment, Prospectus or supplement, as applicable, as proposed to be filed, contains a material misstatement or omission; Notwithstanding the last two sentences, the Company shall not be prohibited from making any filing that is, in the opinion of counsel to the Company, necessary to comply with applicable law;

     (v) [Reserved];

     (vi) make available, subject to customary confidentiality agreements, at reasonable times for inspection by the managing underwriter(s), if any, participating in any disposition pursuant to such Registration Statement and any attorney or accountant retained by any of the underwriter(s) or selling Holders, all financial and other records, pertinent corporate documents and properties of each of the Company and the Guarantors and cause the Company’s and the Guarantor’ officers, directors and employees to supply all information, in each case as shall be reasonably necessary to enable any such Holder, underwriter, attorney or accountant to exercise any applicable responsibilities in connection with such Registration Statement or any post-effective amendment thereto subsequent to the filing thereof and prior to its effectiveness and to participate in meetings with investors to the extent requested by the managing underwriter(s), if any;

     (vii) if requested by any selling Holders or the underwriter(s), if any, promptly incorporate in any Registration Statement or Prospectus, pursuant to a supplement or post-effective amendment if necessary, such information as such selling Holders and underwriter(s),

if any, may reasonably request to have included therein, including, without limitation, information relating to the “Plan of Distribution” of the Transfer Restricted Securities, information with respect to the principal amount of Transfer Restricted Securities being sold to such underwriter(s), the purchase price being paid therefor and any other terms of the offering of the Transfer Restricted Securities to be sold in such offering; and make all required filings of such Prospectus supplement or post-effective amendment as soon as practicable after the Company is notified of the matters to be incorporated in such Prospectus supplement or post-effective amendment;

     (viii) cause the Transfer Restricted Securities covered by the Registration Statement to be rated with the appropriate rating agencies, if so requested by the Holders of a majority in aggregate principal amount of Transfer Restricted Securities covered thereby or the underwriter(s), if any;

     (ix) furnish to each selling Holder and each of the underwriter(s), if any, without charge, at least one copy of the Registration Statement, as first filed with the Commission, and of each amendment thereto, including financial statements and schedules, all documents incorporated by reference therein and all exhibits (including exhibits incorporated therein by reference);

     (x) deliver to each selling Holder and each of the underwriter(s), if any, without charge, as many copies of the Prospectus (including each preliminary prospectus) and any amendment or supplement thereto as such Persons reasonably may request; each of the Company and the Guarantors hereby consents to the use of the Prospectus and any amendment or supplement thereto by each of the selling Holders and each of the underwriter(s), if any, in connection with the offering and the sale of the Transfer Restricted Securities covered by the Prospectus or any amendment or supplement thereto;

     (xi) enter into such agreements (including an underwriting agreement), and make such representations and warranties, and take all such other commercially reasonable actions in connection therewith in order to expedite or facilitate the disposition of the Transfer Restricted Securities pursuant to any Registration Statement contemplated by this Agreement, all to such extent as may be reasonably requested by any Holder of Transfer Restricted Securities or underwriter in connection with any sale or resale pursuant to any Registration Statement contemplated by this Agreement; and whether or not an underwriting agreement is entered into and whether or not the registration is an Underwritten Registration, each of the Company and the Guarantors shall:

     (A) furnish to each selling Holder and each underwriter, if any, in such substance and scope as they may request and as are customarily made by issuers to underwriters in primary underwritten offerings, upon the effectiveness of the Shelf Registration Statement:

     (1) a certificate, dated the date of effectiveness of the Shelf Registration Statement, signed by (y) the President or any Vice President and (z) a principal financial or accounting officer of each of the Company and the Guarantors, confirming, as of the date thereof, the matters set forth

in paragraphs (i), (ii) and (iii) of Section 5(e) of the purchase agreement dated as of March 24, 2010 relating to the 8% Notes (the “8% Notes Purchase Agreement”) as if they applied to the Securities and such other matters as such parties may reasonably request;

     (2) if requested by a majority of the Holders, an opinion, dated the date of effectiveness of the Shelf Registration Statement, of counsel for the Company and the Guarantors, covering the matters set forth in the opinion delivered pursuant to Section 5(c) of the 8% Notes Purchase Agreement as if they applied to the Securities and such other matter as such parties may reasonably request, and in any event including a statement to the effect that such counsel has participated in conferences with officers and other representatives of the Company and the Guarantors, representatives of the independent public accountants for the Company and the Guarantors, representatives of the underwriter(s), if any, and counsel to the underwriter(s), if any, in connection with the preparation of such Registration Statement and the related Prospectus and have considered the matters required to be stated therein and the statements contained therein, although such counsel has not independently verified the accuracy, completeness or fairness of such statements; and that such counsel advises that, on the basis of the foregoing, no facts came to such counsel’s attention that caused such counsel to believe that the applicable Registration Statement, at the time such Registration Statement or any post-effective amendment thereto became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, or that the Prospectus contained in such Registration Statement as of its date, contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. Without limiting the foregoing, such counsel may state further that such counsel assumes no responsibility for, and has not independently verified, the accuracy, completeness or fairness of the financial statements, notes and schedules and other financial data included in any Registration Statement contemplated by this Agreement or the related Prospectus; and

     (3) a customary comfort letter, dated the date of effectiveness of the Shelf Registration Statement, from the Company’s independent accountants, in the customary form and covering matters of the type customarily requested to be covered in comfort letters by underwriters in connection with primary underwritten offerings, without exception;

     (B) set forth in full or incorporate by reference in the underwriting agreement, if any, the indemnification provisions and procedures of Section 7 hereof with respect to all parties to be indemnified pursuant to said Section; and

     (C) deliver such other documents and certificates as may be reasonably requested by such parties to evidence compliance with Section 5(b)(xi)(A) hereof and with any customary conditions contained in the underwriting agreement or other agreement entered into by the Company or any of the Guarantors pursuant to this Section 5(b)(xi), if any.

     If at any time the representations and warranties of the Company and the Guarantors contemplated in Section 5(b)(xi)(A)(1) hereof cease to be true and correct, the Company or the Guarantors shall so advise the underwriter(s), if any, and each selling Holder promptly and, if requested by such Persons, shall confirm such advice in writing;

     (xii) prior to any public offering of Transfer Restricted Securities, cooperate with the selling Holders, the underwriter(s), if any, and their respective counsel in connection with the registration and qualification of the Transfer Restricted Securities under the state securities or blue sky laws of such jurisdictions as the selling Holders or underwriter(s), if any, may request and do any and all other acts or things necessary or advisable to enable the disposition in such jurisdictions of the Transfer Restricted Securities covered by the Shelf Registration Statement; provided, however, that neither the Company nor the Guarantors shall be required to register or qualify as a foreign corporation where it is not then so qualified or to take any action that would subject it to the service of process in suits or to taxation, other than as to matters and transactions relating to the Registration Statement, in any jurisdiction where it is not then so subject;

     (xiii) cooperate with the selling Holders and the underwriter(s), if any, to facilitate the timely preparation and delivery of certificates representing Transfer Restricted Securities to be sold and not bearing any restrictive legends; and enable such Transfer Restricted Securities to be in such denominations and registered in such names as the Holders or the underwriter(s), if any, may request at least two Business Days prior to any sale of Transfer Restricted Securities made by such Holders or underwriter(s);

     (xiv) use its commercially reasonable efforts to cause the Transfer Restricted Securities covered by the Registration Statement to be registered with or approved by such other governmental agencies or authorities as may be necessary to enable the seller or sellers thereof or the underwriter(s), if any, to consummate the disposition of such Transfer Restricted Securities, subject to the proviso contained in Section 5(b)(xii) hereof;

     (xv) if any fact or event contemplated by Section 5(b)(iii)(D) hereof shall exist or have occurred, prepare a supplement or post-effective amendment to the Registration Statement or related Prospectus or any document incorporated therein by reference or file any other required document so that, as thereafter delivered to the purchasers of Transfer Restricted Securities, the Prospectus will not contain an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein not misleading;

     (xvi) provide a CUSIP number for all Securities not later than the effective date of the Registration Statement covering such Securities and provide the Trustee under the

Indenture with printed certificates for such Securities which are in a form eligible for deposit with the Depository Trust Company and take all other action necessary to ensure that all such Securities are eligible for deposit with the Depository Trust Company;

     (xvii) cooperate and assist in any filings required to be made with the FINRA and in the performance of any due diligence investigation by any underwriter (including any “qualified independent underwriter”) that is required to be retained in accordance with the rules and regulations of the FINRA;

     (xviii) otherwise use its commercially reasonable efforts to comply with all applicable rules and regulations of the Commission, and make generally available to its security holders, as soon as practicable, a consolidated earnings statement meeting the requirements of Rule 158 (which need not be audited) for the twelve-month period (A) commencing at the end of any fiscal quarter in which Transfer Restricted Securities are sold to underwriters in a firm commitment or best efforts Underwritten Offering or (B) if not sold to underwriters in such an offering, beginning with the first month of the Company’s first fiscal quarter commencing after the effective date of the Registration Statement;

     (xix) cause the Indenture to be qualified under the Trust Indenture Act not later than the effective date of the first Registration Statement required by this Agreement, and, in connection therewith, cooperate with the Trustee and the Holders of Transfer Restricted Securities to effect such changes to the Indenture as may be required for such Indenture to be so qualified in accordance with the terms of the Trust Indenture Act; and to execute and use its commercially reasonable efforts to cause the Trustee to execute, all documents that may be required to effect such changes and all other forms and documents required to be filed with the Commission to enable such Indenture to be so qualified in a timely manner;

     (xx) cause all Securities covered by the Registration Statement to be listed on each securities exchange or automated quotation system on which similar securities issued by the Company are then listed if reasonably requested by the Holders of a majority in aggregate principal amount of Transfer Restricted Securities or the managing underwriter(s), if any; and

     (xxi) provide promptly to each Holder upon request each document filed with the Commission pursuant to the requirements of Section 13 and Section 15 of the Exchange Act.

     Each Holder agrees by acquisition of a Transfer Restricted Security that, upon receipt of any notice from the Company of the existence of any fact of the kind described in Section 5(b)(iii)(D) hereof, such Holder will forthwith discontinue disposition of Transfer Restricted Securities pursuant to the applicable Registration Statement until such Holder’s receipt of the copies of the supplemented or amended Prospectus contemplated by Section 5(b)(xvi) hereof, or until it is advised in writing (the “Advice”) by the Company that the use of the Prospectus may be resumed, and has received copies of any additional or supplemental filings that are incorporated by reference in the Prospectus. If so directed by the Company, each Holder will deliver to the

Company (at the Company’s expense) all copies, other than permanent file copies then in such Holder’s possession, of the Prospectus covering such Transfer Restricted Securities that was current at the time of receipt of such notice. In the event the Company shall give any such notice, the time period regarding the effectiveness of such Registration Statement set forth in Section 3 or 4 hereof, as applicable, shall be extended by the number of days during the period from and including the date of the giving of such notice pursuant to Section 5(b)(iii)(D) hereof to and including the date when each selling Holder covered by such Registration Statement shall have received the copies of the supplemented or amended Prospectus contemplated by Section 5(b)(xvi) hereof or shall have received the Advice; provided, however, that no such extension shall be taken into account in determining whether Additional Interest is due pursuant to Section 4 hereof or the amount of such Additional Interest, it being agreed that the Company’s option to suspend use of a Registration Statement pursuant to this paragraph shall be treated as a Registration Default for purposes of Section 4 hereof.

     SECTION 6. Registration Expenses.

     (a) All reasonable and documented expenses incident to the Company’s and the Guarantor’s performance of or compliance with this Agreement will be borne by the Company and the Guarantors, jointly and severally, regardless of whether a Registration Statement becomes effective, including, without limitation: (i) all registration and filing fees and expenses (including filings made by any Holder with the FINRA (and, if applicable, the fees and expenses of any “qualified independent underwriter” and one counsel to such person, that may be required by the rules and regulations of the FINRA)); (ii) all fees and expenses of compliance with federal securities and state securities or blue sky laws; (iii) all expenses of printing, messenger and delivery services and telephone; (iv) all fees and disbursements of counsel for the Company, the Guarantors and, subject to Section 6(b) hereof, all reasonable fees and disbursements of one counsel to the Holders of Transfer Restricted Securities; (v) all application and filing fees in connection with listing the Securities on a securities exchange or automated quotation system pursuant to the requirements thereof, if requested pursuant to Section 5(b); and (vi) all fees and disbursements of independent certified public accountants of the Company and the Guarantors (including the expenses of any special audit and comfort letters required by or incident to such performance).

     Each of the Company and the Guarantors will, in any event, bear its internal expenses (including, without limitation, all salaries and expenses of its officers and employees performing legal or accounting duties), the expenses of any annual audit and the fees and expenses of any Person, including special experts, retained by the Company or the Guarantors.

     (b) In connection with any Registration Statement required by this Agreement, the Company and the Guarantors, jointly and severally, will reimburse the Holders of Transfer Restricted Securities being registered pursuant to such Registration Statement for the reasonable fees and disbursements of not more than one counsel, which counsel shall be chosen by the Holders of a majority in principal amount of the Transfer Restricted Securities for whose benefit such Registration Statement is being prepared.

     SECTION 7. Indemnification.

     (a) The Company and the Guarantors, jointly and severally, agree to indemnify and hold harmless (i) each Holder and (ii) each Person, if any, who controls (within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act) any Holder (any of the Persons referred to in this clause (ii) being hereinafter referred to as a “controlling person”) and (iii) the respective officers, directors, partners, employees, representatives and agents of any Holder or any controlling person (any Person referred to in clause (i), (ii) or (iii) may hereinafter be referred to as an “Indemnified Holder”), to the fullest extent lawful, from and against any and all losses, claims, damages, liabilities, judgments, actions and reasonable expenses (including, without limitation, and as incurred, reimbursement of all reasonable costs of investigating, preparing, pursuing, settling, compromising, paying or defending any claim or action, or any investigation or proceeding by any governmental agency or body, commenced or threatened, including the reasonable fees and expenses of counsel to any Indemnified Holder), joint or several, directly or indirectly caused by, related to, based upon, arising out of or in connection with any untrue statement or alleged untrue statement of a material fact contained in any Registration Statement or Prospectus (or any amendment or supplement thereto), or any omission or alleged omission to state therein 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, except insofar as such losses, claims, damages, liabilities or expenses are caused by an untrue statement or omission or alleged untrue statement or omission that is made in reliance upon and in conformity with information relating to any of the Holders, its directors, officers, employees or controlling persons furnished in writing to the Company by any of the Holders expressly for use therein. This indemnity agreement shall be in addition to any liability which the Company or any Guarantor may otherwise have.

     In case any action or proceeding (including any governmental or regulatory investigation or proceeding) shall be brought or asserted against any of the Indemnified Holders with respect to which indemnity may be sought against the Company or the Guarantors, such Indemnified Holder (or the Indemnified Holder controlled by such controlling person) shall promptly notify the Company and the Guarantors in writing; provided, however, that the failure to give such notice shall not relieve any of the Company or the Guarantors of its obligations pursuant to this Agreement. Such Indemnified Holder shall have the right to employ its own counsel in any such action and the fees and expenses of such counsel shall be paid, as incurred, by the Company and the Guarantors (regardless of whether it is ultimately determined that an Indemnified Holder is not entitled to indemnification hereunder). The Company and the Guarantors shall not, in connection with any one such action or proceeding or separate but substantially similar or related actions or proceedings in the same jurisdiction arising out of the same general allegations or circumstances, be liable for the reasonable fees and expenses of more than one separate firm of attorneys (in addition to any local counsel) at any time for such Indemnified Holders, which firm shall be designated by the Holders. The Company and the Guarantors shall be liable for any settlement of any such action or proceeding effected with the Company’s and the Guarantors’ prior written consent, which consent shall not be withheld unreasonably, and each of the Company and the Guarantors agree to indemnify and hold harmless any Indemnified Holder from and against any loss, claim, damage, liability or expense by reason of any settlement of any action effected with the written consent of the Company and the Guarantors. The Company and the Guarantors shall not, without the prior written consent of each Indemnified Holder, settle or compromise or

consent to the entry of judgment in or otherwise seek to terminate any pending or threatened action, claim, litigation or proceeding in respect of which indemnification or contribution may be sought hereunder (whether or not any Indemnified Holder is a party thereto), unless such settlement, compromise, consent or termination (i) includes an unconditional release of each Indemnified Holder from all liability arising out of such action, claim, litigation or proceeding and (ii) does not include any statements as to or any findings of fault, culpability or failure to act by or on behalf of any indemnified party.

     (b) Each Holder of Transfer Restricted Securities agrees, severally and not jointly, to indemnify and hold harmless the Company, the Guarantors and their respective directors, officers of the Company and the Guarantors who sign a Registration Statement, and any Person controlling (within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act) the Company or any of the Guarantors, and the respective officers, directors, partners, employees, representatives and agents of each such Person, to the same extent as the foregoing indemnity from the Company and the Guarantors to each of the Indemnified Holders, but only with respect to claims and actions based on information relating to such Holder furnished in writing by such Holder expressly for use in any Registration Statement; provided that the total amount to be indemnified by such Holder pursuant to this Section 7(b) shall be limited to the net proceeds (after deducting underwriters’ discounts and commissions) received by such Holder in the offering to which such Registration Statement relates. In case any action or proceeding shall be brought against the Company, the Guarantors or their respective directors or officers or any such controlling person in respect of which indemnity may be sought against a Holder of Transfer Restricted Securities, such Holder shall have the rights and duties given the Company and the Guarantors, and the Company, the Guarantors, their respective directors and officers and such controlling person shall have the rights and duties given to each Holder by the preceding paragraph.

     (c) If the indemnification provided for in this Section 7 is unavailable to an indemnified party under Section 7(a) or (b) hereof (other than by reason of exceptions provided in those Sections) in respect of any losses, claims, damages, liabilities, judgments, actions or expenses referred to therein, then each applicable indemnifying party, in lieu of indemnifying such indemnified party, shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages, liabilities or expenses in such proportion as is appropriate to reflect the relative benefits received by the Company and the Guarantors, on the one hand, and the Holders, on the other hand, from the Initial Placement (which in the case of the Company and the Guarantors shall be deemed to be equal to the total gross proceeds to the Company and the Guarantors from the Initial Placement), the amount of Additional Interest which did not become payable as a result of the filing of the Registration Statement resulting in such losses, claims, damages, liabilities, judgments actions or expenses, and such Registration Statement, or if such allocation is not permitted by applicable law, the relative fault of the Company and the Guarantors, on the one hand, and the Holders, on the other hand, in connection with the statements or omissions which resulted in such losses, claims, damages, liabilities or expenses, as well as any other relevant equitable considerations. The relative fault of the Company on the one hand and of the Indemnified Holder on the other shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company or any of the Guarantors, on the one hand, or the Indemnified Holders, on the other hand, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The amount paid or payable by a party as a result of the losses, claims, damages, liabilities and expenses referred to above shall be deemed to include, subject to the limitations set forth in the second paragraph of Section 7(a) hereof, any legal or other fees or expenses reasonably incurred by such party in connection with investigating or defending any action or claim.

     The Company, the Guarantors and each Holder of Transfer Restricted Securities agree that it would not be just and equitable if contribution pursuant to this Section 7(c) were determined by pro rata allocation (even if the Holders were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to in the immediately preceding paragraph. The amount paid or payable by an indemnified party as a result of the losses, claims, damages, liabilities or expenses referred to in the immediately preceding paragraph shall be deemed to include, subject to the limitations set forth above, 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 ▇▇▇▇▇▇▇ ▇, ▇▇▇▇ of the Holders (and its related Indemnified Holders) shall be required to contribute, in the aggregate, any amount in excess of the amount by which the total net proceeds (after deducting underwriters’ discounts and commissions) received by such Holder with respect to the Securities exceeds the amount of any damages which such Holder has otherwise been required to pay by reason of such 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 Holders’ obligations to contribute pursuant to this Section 7(c) are several in proportion to the respective principal amount of Transfer Restricted Securities held by each of the Holders hereunder and not joint.

     SECTION 8. Rule 144A. Each of the Company and the Guarantors hereby agrees with each Holder, for so long as any Transfer Restricted Securities remain outstanding, to make available to any Holder or beneficial owner of Transfer Restricted Securities in connection with any sale thereof and any prospective purchaser of such Transfer Restricted Securities from such Holder or beneficial owner, the information required by Rule 144A(d)(4) under the Securities Act in order to permit resales of such Transfer Restricted Securities pursuant to Rule 144A under the Securities Act.

     SECTION 9. Participation in Underwritten Registrations. No Holder may participate in any Underwritten Registration hereunder unless such Holder (a) agrees to sell such Holder’s Transfer Restricted Securities on the basis provided in any underwriting arrangements approved by the Persons entitled hereunder to approve such arrangements and (b) completes and executes all reasonable questionnaires, powers of attorney, indemnities, underwriting agreements, lock-up letters and other documents required under the terms of such underwriting arrangements.

     SECTION 10. Selection of Underwriters. The Holders of Transfer Restricted Securities covered by the Shelf Registration Statement who desire to do so may sell such Transfer Restricted Securities in an Underwritten Offering. In any such Underwritten Offering, the investment banker(s) and managing underwriter(s) that will administer such offering will be selected by the Holders of a majority in aggregate principal amount of the Transfer Restricted Securities included in such offering; provided, however, that such investment banker(s) and managing underwriter(s) must be reasonably satisfactory to the Company.

     SECTION 11. Miscellaneous.

     (a) Remedies. Each of the Company and the Guarantors hereby agrees that monetary damages would not be adequate compensation for any loss incurred by reason of a breach by it of the provisions of this Agreement and hereby agree to waive the defense in any action for specific performance that a remedy at law would be adequate.

     (b) No Inconsistent Agreements. Each of the Company and the Guarantors will not on or after the date of this Agreement enter into any agreement with respect to its securities that is inconsistent with the rights granted to the Holders in this Agreement or otherwise conflicts with the provisions hereof. Neither the Company nor any of the Guarantors has not previously entered into any agreement granting any registration rights with respect to its securities to any Person. The rights granted to the Holders hereunder do not in any way conflict with and are not inconsistent with the rights granted to the holders of the Company’s or any of the Guarantors’ securities under any agreement in effect on the date hereof.

     (c) Amendments and Waivers. The provisions of this Agreement may not be amended, modified or supplemented, and waivers or consents to or departures from the provisions hereof may not be given unless the Company has (i) in the case of Section 4 hereof and this Section 11(c)(i), obtained the written consent of Holders of all outstanding Transfer Restricted Securities and (ii) in the case of all other provisions hereof, obtained the written consent of Holders of a majority of the outstanding principal amount of Transfer Restricted Securities (excluding any Transfer Restricted Securities held by the Company or its Affiliates).

     (d) Notices. All notices and other communications provided for or permitted hereunder shall be made in writing by hand-delivery, first-class mail (registered or certified, return receipt requested), telex, telecopier, or air courier guaranteeing overnight delivery:

     (i) if to a Holder, at the address set forth on the signature page hereto or as set forth on the records of the Registrar under the Indenture, with a copy to the Registrar under the Indenture; and

     (ii) if to the Company:

Lyondell Chemical Company
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Facsimile: (▇▇▇) ▇▇▇-▇▇▇▇
Attention: ▇▇▇▇▇▇ ▇. ▇’▇▇▇▇▇

     All such notices and communications shall be deemed to have been duly given: at the time delivered by hand, if personally delivered; five Business Days after being deposited in the mail, postage prepaid, if mailed; when answered back, if telexed; when receipt acknowledged, if telecopied; and on the next Business Day, if timely delivered to an air courier guaranteeing overnight delivery.

     Copies of all such notices, demands or other communications shall be concurrently delivered by the Person giving the same to the Trustee at the address specified in the Indenture.

     (e) Successors and Assigns. This Agreement shall inure to the benefit of and be binding upon the successors and assigns of each of the parties, including, without limitation, and without the need for an express assignment, subsequent Holders of Transfer Restricted Securities; provided, however, that this Agreement shall not inure to the benefit of or be binding upon a successor or assign of a Holder unless and to the extent such successor or assign acquired Transfer Restricted Securities from such Holder.

     (f) Counterparts. This Agreement may be executed in any number of counterparts and by the parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement.

     (g) Headings. The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.

     (h) 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 LAW RULES THEREOF.

     (i) Severability. In the event that any one or more of the provisions contained herein, or the application thereof in any circumstance, is held invalid, illegal or unenforceable, the validity, legality and enforceability of any such provision in every other respect and of the remaining provisions contained herein shall not be affected or impaired thereby.

     (j) Entire Agreement. This Agreement is intended by the parties as a final expression of their agreement and intended to be a complete and exclusive statement of the agreement and understanding of the parties hereto in respect of the subject matter contained herein. There are no restrictions, promises, warranties or undertakings, other than those set forth or referred to herein with respect to the registration rights granted by the Company with respect to the Transfer Restricted Securities. This Agreement supersedes all prior agreements and understandings between the parties with respect to such subject matter.

[Signature pages to follow]

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date first written above.

(Signature Page for Notes Registration Rights Agreement)

(Signature Page for Notes Registration Rights Agreement)

Address:

▇▇ ▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
▇-▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇, Grand Duchy of Luxembourg

(Signature Page for Notes Registration Rights Agreement)

Address:

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▇-▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇▇▇ of Luxembourg

(Signature Page for Notes Registration Rights Agreement)

Address:

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▇-▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇, Grand Duchy of Luxembourg

(Signature Page for Notes Registration Rights Agreement)

Address:

▇▇ ▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
▇-▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇, Grand Duchy of Luxembourg

(Signature Page for Notes Registration Rights Agreement)

Address:

▇▇ ▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
▇-▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇, Grand Duchy of Luxembourg

(Signature Page for Notes Registration Rights Agreement)