EXHIBIT 10.8
                                                                  EXECUTION COPY
                FIRST AMENDMENT TO GUARANTY BY MIDSTREAM ENTITIES
         This First Amendment dated as of October 31, 2002 (this "Amendment") to
the Guaranty dated as of July 31, 2002 (as amended and modified from time to
time, the "Guaranty"), is executed by certain Midstream Subsidiaries (the
"Guarantors"), in favor of Citibank, N.A., as surety administrative agent
("Agent") for the benefit of the holders of the Secured Obligations. All
capitalized terms used herein and not otherwise defined shall have the meanings
ascribed to such terms in the Guaranty.
                                   WITNESSETH:
         WHEREAS, the parties hereto have agreed to amend certain provisions of
the Guaranty;
         NOW THEREFORE, in consideration of the mutual covenants contained
herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree that the
Guaranty is hereby amended as follows:
1.       Amendments
         (a) Pursuant to the terms of those two certain Consent and Waivers each
         dated as of September 20, 2002, by and among the Company and the other
         signatories thereto, the Guaranty was amended to (i) remove ▇▇▇▇▇▇▇▇
         Field Services - Gulf Coast Company, L.P., as a Guarantor and (ii) add
         ▇▇▇▇▇▇▇▇ Gulf Coast Gathering Company, LLC, as a Guarantor. Pursuant to
         this Amendment, the following additional parties are added as
         Guarantors: WFS - Pipeline Company; WFS Gathering Company, L.L.C.;
         ▇▇▇▇▇▇▇▇ Field Services - Matagorda Offshore Company, LLC; ▇▇▇▇▇▇▇▇ Gas
         Processing - Mid Continent Region Company; WFS-OCS Gathering Co.;
         HI-BOL Pipeline Company; ▇▇▇▇▇▇ Gathering Company, L.L.C.; ▇▇▇▇▇▇▇▇
         Petroleum Services, LLC; Longhorn Enterprises of Texas, Inc.; and
         ▇▇▇▇▇▇▇▇ ▇▇ LLC.
         (b) The second sentence of Section 1 of the Guaranty is hereby amended
         by adding at the end of such sentence the following proviso: ";
         provided that Guaranteed Obligations shall not include any increases
         which occur after the date hereof in the principal amount of the
         obligations under the Credit Documents (other than increases in the
         principal amount of such obligations that are provided for as of the
         date of the execution of this Agreement but not yet funded) and/or the
         commitments to advance funds or letters of credit thereunder".
         (c) Section 8.01 of the Guaranty is hereby amended and restated in its
         entirety and replaced with the following:
                  "8.01. Amendments, Etc. Any amendment or waiver to this
                  Guaranty shall be effective only if approved by Financial
                  Institutions holding at least 51% of the principal amount of
                  the Guaranteed Obligations at the time thereof and only in the
                  specific instance and for the specific purpose for which
                  given. Provided,
                  however, any amendment or waiver releasing any Guarantor from
                  any liability hereunder shall require the unanimous consent of
                  all Financial Institutions and be effective only in the
                  specific instance and for the specific purpose for which
                  given. Notwithstanding the foregoing, any release of a
                  Guarantor as permitted in Section 5.2(e) of the L/C Credit
                  Agreement and Section 5.02(l) of the Multiyear ▇▇▇▇▇▇▇▇ Credit
                  Agreement (without giving effect to any amendment or waiver of
                  such Sections except such amendments or waivers that are
                  unanimously approved under the terms of Section 9.1 of the L/C
                  Credit Agreement and Section 8.01 of the Multiyear ▇▇▇▇▇▇▇▇
                  Credit Agreement) shall not require any consent beyond
                  compliance with the appropriate provisions set forth in such
                  credit agreements. No Financial Institution may be removed as
                  a beneficiary of this Guaranty without such Financial
                  Institution's prior written consent."
         (d) Section 8.06 of the Guaranty is hereby amended and restated in its
         entirety and replaced with the following:
                  "Section 8.06 Incorporated Definitions and Provisions. All
                  defined terms and other provisions that are incorporated into
                  this Guaranty by reference to other agreements shall
                  incorporate into this Guaranty the provisions of such other
                  agreements that exist as of the date hereof; however, such
                  provisions shall be automatically modified herein by any
                  amendment or modification that takes place after the date
                  hereof in such other referenced agreement(s)."
         (e) The following Section 8.08 is hereby added to the Guaranty:
                  "Section 8.08 Joinder. Pursuant to the terms of the Credit
                  Documents certain Subsidiaries (hereafter referred to as the
                  "Joining Subsidiaries") may desire to or be required to join
                  this Guaranty as Guarantors. In connection with any such
                  joinder the Joining Subsidiary shall execute and deliver (a) a
                  joinder agreement substantially in the form of the joinder
                  agreement attached hereto as Schedule I and (b) authorization
                  documentation, corporate documentation, perfection
                  documentation and opinion letters satisfactory to the Agent
                  reflecting the status of such Joining Subsidiary and the
                  enforceability of such agreements with respect to such Joining
                  Subsidiary and reasonable opinions with respect to such
                  Joining Subsidiary."
         (f) A new Schedule I to the Security Agreement is hereby added which is
         the document attached as Schedule I hereto.
2. Conditions to Effectiveness. This Amendment shall be deemed effective (the
"Effective Date") upon the satisfaction of the conditions precedent as set out
in Section 3.1 of that certain Amended and Restated Credit Agreement, dated as
of October 31, 2002, among Company and the Financial Institutions named therein,
without giving effect to the terms of Section 3.3.
3. Governing Law. This Amendment shall be governed by, and construed and
enforced in accordance with, the laws of the State of New York.
                                      -2-
4. Reference to and Effect on the Guaranty. The amendments set forth herein are
limited precisely as written and shall not be deemed to be a consent or waiver
to, or modification of any other term or condition in the Guaranty or any of the
documents referred to therein. Except as expressly amended and consented hereby,
the terms and conditions of the Guaranty shall continue in full force and
effect, and as amended hereby, the Guaranty is ratified and confirmed in all
respects. On and after the Effective Date, the Guaranty shall be deemed to mean
the Guaranty as amended hereby.
5. Counterparts. This Amendment may be executed in several counterparts, each of
which shall be deemed an original, but all of which together shall constitute
one and the same agreement.
Schedule I:   Form of Joinder Agreement
                                      -3-
         IN WITNESS WHEREOF, the parties hereto, acting through their duly
authorized representatives, have caused this amendment to be signed in their
respective names.
                                    AGENT:
                                    CITIBANK, N.A., as Agent (as defined in the
                                    Guaranty)
                                    By /s/ ▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Vice President
                                    AGENT AND COLLATERAL AGENT:
                                    CITICORP USA, INC., as Agent and Collateral
                                    Agent
                                    By /s/ ▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Vice President
                                    BANKS AND ISSUING BANKS:
                                    CITIBANK N.A., as Issuing Bank
                                    By /s/ ▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Vice President
                                    CITICORP USA, INC.
                                    By /s/ ▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Vice President
                                    THE BANK OF NOVA SCOTIA, as Canadian Issuing
                                    Bank and Bank
                                    By:
                                        ----------------------------------------
                                    Name:
                                    Title:
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    BANK OF AMERICA, N.A., as Issuing Bank and
                                    Bank
                                    By /s/ ▇▇▇▇▇▇ ▇. ▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇
                                    Title: Managing Director
                                    ▇▇ ▇▇▇▇▇▇ CHASE BANK
                                    By: /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                    Title: Vice President
                                    TORONTO DOMINION (TEXAS), INC.
                                    By: /s/ ▇▇▇▇ ▇▇▇▇
                                        ----------------------------------------
                                    Name: ▇▇▇▇ ▇▇▇▇
                                    Title: Vice President
                                    CREDIT LYONNAIS NEW YORK BRANCH
                                    By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                        ----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇ ▇▇▇▇▇ CAPITAL CORP.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇. ▇▇▇▇▇▇
                                        ----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇. ▇▇▇▇▇▇
                                    Title: Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    ▇▇▇▇▇▇ COMMERCIAL PAPER INC.
                                    By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇
                                        ----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇
                                    Title: Authorized Signatory
                                    CO-SYNDICATION AGENTS:
                                    JPMORGAN CHASE BANK
                                    (formerly known as
                                    THE CHASE MANHATTAN BANK),
                                    As Co-Syndication Agent
                                    By /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                    Title: Vice President
                                    COMMERZBANK AG,
                                    as Co-Syndication Agent
                                    By /s/ ▇▇▇▇▇ ▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇▇▇▇▇▇
                                    Title: Senior Vice Pres. and Manager
                                    By /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    DOCUMENTATION AGENT:
                                    CREDIT LYONNAIS NEW YORK BRANCH
                                    as Documentation Agent
                                    By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                        ----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    BANKS:
                                    CITICORP, USA, INC.
                                    By /s/ ▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    THE BANK OF NOVA SCOTIA
                                    By: /s/ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇. ▇▇▇▇
                                    Title: Senior Manager
                                    BANK OF AMERICA, N.A.
                                    By /s/ ▇▇▇▇▇▇ ▇. ▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇
                                    Title: Managing Director
                                    BANK ONE, N.A. (MAIN OFFICE - CHICAGO)
                                    By /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇
                                    Title: Director
                                    JPMORGAN CHASE BANK
                                    (formerly known as
                                    THE CHASE MANHATTAN BANK),
                                    By /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                    Title: Vice President
                                    COMMERZBANK AG
                                    NEW YORK AND GRAND CAYMAN BRANCHES
                                    By /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    By /s/ W. ▇▇▇▇▇ ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: W. ▇▇▇▇▇ ▇▇▇▇▇▇▇
                                    Title: Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    CREDIT LYONNAIS NEW YORK BRANCH
                                    By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                        ----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    NATIONAL WESTMINSTER PLC
                                    By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇
                                        ----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇
                                    Title: Senior Vice President
                                    ABN AMRO BANK, N.V.
                                    By /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇, ▇▇.
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇, ▇▇.
                                    Title: Group Vice President
                                    By /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Vice President
                                    BANK OF MONTREAL
                                    By /s/ ▇▇▇▇ ▇▇▇ ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇▇▇ ▇▇▇▇▇
                                    Title: Director
                                    THE BANK OF NEW YORK
                                    By /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
                                    Title: Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    BARCLAYS BANK PLC
                                    By /s/ ▇▇▇▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Director, Loan Transaction Management
                                    CIBC INC.
                                    By /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇
                                    Title: Managing Director
                                    CREDIT SUISSE FIRST BOSTON
                                    By /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Director
                                    By /s/ ▇▇▇ ▇. ▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇ ▇. ▇▇▇▇▇▇
                                    Title: Associate
                                    ROYAL BANK OF CANADA
                                    By /s/ ▇▇▇▇▇ ▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇▇▇▇▇▇
                                    Title: Senior Manager
                                    THE BANK OF TOKYO-MITSUBISHI, LTD., HOUSTON
                                    AGENCY
                                    By /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                    Title: Vice President and Manager
                                    By /s/ ▇▇▇ Fort
                                       -----------------------------------------
                                    Name: ▇▇▇ Fort
                                    Title: Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    FLEET NATIONAL BANK
                                    f/k/a Bank Boston, N.A.
                                    By /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Authorized Officer
                                    SOCIETE GENERALE, SOUTHWEST AGENCY
                                    By /s/ J. ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇, ▇▇.
                                       -----------------------------------------
                                    Name: J. ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇, ▇▇.
                                    Title: Managing Director
                                    TORONTO DOMINION (TEXAS), INC.
                                    By: /s/ ▇▇▇▇ ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇▇▇▇
                                    Title: Vice President
                                    UBS AG, STAMFORD BRANCH
                                    By /s/ ▇▇▇▇▇ ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇▇▇▇▇
                                    Title: Director - Recovery Management
                                    By ▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Executive Director - Recovery
                                           Management
                                    ▇▇▇▇▇ FARGO BANK TEXAS, N.A.
                                    By /s/ J. ▇▇▇▇ ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: J. ▇▇▇▇ ▇▇▇▇▇▇▇▇▇
                                    Title: Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    WESTLB AG, NEW YORK BRANCH
                                    By /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Director
                                    Name: ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇
                                    Title: Managing Director - Credit Department
                                    CREDIT AGRICOLE INDOSUEZ
                                    By /s/ ▇▇▇▇▇ ▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇▇▇▇▇▇
                                    Title: Vice President
                                    By /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                    Title: Vice President, Senior Relationship
                                           Manager
                                    SUNTRUST BANK
                                    By /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: Director
                                    ARAB BANKING CORPORATION (B.S.C.)
                                    By /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Deputy General Manager
                                    By /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Vice President Head of Credit
                                    BANK OF CHINA, NEW YORK BRANCH
                                    By
                                    Name:
                                    Title:
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    BANK OF OKLAHOMA, N.A.
                                    By
                                       -----------------------------------------
                                    Name:
                                    Title:
                                    BNP PARIBAS, HOUSTON AGENCY
                                    By /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇
                                    Title: Vice President
                                    By /s/ ▇▇▇▇ ▇. ▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇
                                    Title: Director
                                    DZ BANK AG DEUTSCHE
                                    ZENTRALGENOSSENSCHAFTSBANK, NEW YORK BRANCH
                                    By /s/ ▇▇▇▇ ▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇▇▇▇▇▇▇▇
                                    Title: Senior V.P.
                                    By /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                    Title: Vice President
                                    KBC BANK N.V.
                                    By /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
                                    Title: First Vice President
                                    By /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                    Title: First Vice President
                                    WACHOVIA BANK, N.A.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    MIZUHO CORPORATE BANK, LTD
                                    By /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇
                                    Title: Senior Vice President and Manager
                                    SUMITOMO MITSUI BANKING CORPORATION
                                    By /s/ ▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    COMMERCE BANK, N.A.
                                    By /s/ ▇▇▇▇▇▇ ▇. Block
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇ ▇. Block
                                    Title: Senior Vice President
                                    ROYAL BANK OF SCOTLAND
                                    Name:
                                    Title:
                                    RZB FINANCE, LLC
                                    By
                                       -----------------------------------------
                                    Name:
                                    Title:
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    WORTHINGTON GENERATION, L.L.C.
                                    By: /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: President
                                    ▇▇▇▇▇▇▇▇ REFINING & MARKETING, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
                                    ▇▇▇▇▇▇▇▇ PETROLEUM SERVICES, LLC
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇▇ PETROLEUM PIPELINE SYSTEMS, INC.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇▇ MID-SOUTH PIPELINES, LLC
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    ▇▇▇▇▇▇▇▇ GENERATION COMPANY-HAZLETON
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Vice President
                                    ▇▇▇▇▇▇▇▇ OLEFINS, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
                                    ▇▇▇▇▇▇▇▇ OLEFINS FEEDSTOCK PIPELINES, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
                                    ▇▇▇▇▇▇▇▇ NATURAL GAS LIQUIDS, INC.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇▇ MIDSTREAM NATURAL GAS LIQUIDS, INC.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    ▇▇▇▇▇▇▇▇ MERCHANT SERVICES COMPANY, INC.
                                    By: /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: President
                                    ▇▇▇▇▇▇▇▇ MEMPHIS TERMINAL, INC.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
                                    ▇▇▇▇▇▇▇▇ GULF COAST GATHERING COMPANY, LLC
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
                                    ▇▇▇▇▇▇▇▇ ▇▇, LLC
                                    By: /s/ ▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇
                                    Title: President and Chief Executive Officer
                                    ▇▇▇▇▇▇▇▇ GENERATING MEMPHIS, LLC
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    ▇▇▇▇▇▇▇▇ GAS PROCESSING - WAMSUTTER COMPANY.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇▇ GAS PROCESSING COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇▇ GAS PROCESSING - MID-CONTINENT
                                    REGION COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇▇ FIELD SERVICES GROUP, INC.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇▇ FIELD SERVICES COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    ▇▇▇▇▇▇▇▇ FIELD SERVICES - MATAGORDA OFFSHORE
                                    COMPANY, LLC
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
                                    ▇▇▇▇▇▇▇▇ EXPRESS, INC. (DE)
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Chief Executive Officer
                                    ▇▇▇▇▇▇▇▇ EXPRESS INC. (AK)
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Chief Executive Officer
                                    ▇▇▇▇▇▇▇▇ ETHANOL SERVICES, INC.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇
                                    Title: Treasurer
                                    ▇▇▇▇▇▇▇▇ ENERGY SERVICES, LLC
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    ▇▇▇▇▇▇▇▇ ENERGY MARKETING & TRADING COMPANY
                                    By: /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: President
                                    ▇▇▇▇▇▇▇▇ BIO-ENERGY, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
                                    ▇▇▇▇▇▇▇▇ ALASKA PIPELINE COMPANY, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇▇▇ ALASKA PETROLEUM, INC.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Chief Executive Officer
                                    ▇▇▇▇▇▇▇▇ ALASKA AIR CARGO PROPERTIES, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Chief Executive Officer
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    WFS-OFFSHORE GATHERING COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    WFS-NGL PIPELINE COMPANY, INC.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    WFS-LIQUIDS COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    WFS GATHERING COMPANY, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
                                    WFS ENTERPRISES, INC.
                                    By: /s/ ▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇
                                    Title: Treasurer
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    WFS - PIPELINE COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    WFS - OCS GATHERING CO.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    NORTH PADRE ISLAND SPINDOWN, INC.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    MEMPHIS GENERATION, L.L.C.
                                    By: /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                    Title: President
                                    MAPL INVESTMENTS, INC.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    MAPCO INC.
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    LONGHORN ENTERPRISES OF TEXAS, INC.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇ PIPELINE COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    HI-BOL PIPELINE COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
                                    ▇▇▇▇▇▇ GATHERING COMPANY, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Assistant Treasurer
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                    GAS SUPPLY, L.L.C.
                                    By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇▇ ▇. ▇▇▇▇
                                    Title: Senior Vice President
                                    BLACK MARLIN PIPELINE COMPANY
                                    By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                       -----------------------------------------
                                    Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
                                    Title: Senior Vice President
SIGNATURE PAGE TO
FIRST AMENDMENT TO MIDSTREAM GUARANTY
                                   SCHEDULE I
                                       TO
                                    GUARANTY
                            FORM OF JOINDER AGREEMENT
                                JOINDER AGREEMENT
                          (name of joining subsidiary)
                               [_________, _____]
         This Joinder Agreement is entered into to join [Joining Subsidiary] as
an additional guarantor to the Guaranty dated as of July 31, 2002 (as amended,
supplemented or otherwise modified from time to time, the "Midstream Guaranty"),
which was executed by THE ▇▇▇▇▇▇▇▇ COMPANIES, INC. (the "Company"), a Delaware
corporation, and certain Midstream Subsidiaries.
         [Joining Subsidiary], a [_________ corporation] (the "Subsidiary"),
hereby agrees with CITIBANK, N.A., as surety administrative agent for the
Financial Institution (as such term is defined in the Midstream Guaranty) as
follows:
         All capitalized terms used herein and not defined herein shall have the
meanings ascribed to such terms in the Amended and Restated Credit Agreement,
dated as of October 31, 2002, by and among The ▇▇▇▇▇▇▇▇ Companies, Inc., the
various lenders as are or may become parties thereto; the Issuing Banks, and
Citicorp USA, Inc., as Agent and Collateral Agent (as further amended, modified,
supplemented, renewed, extended or restated from time to time, the "Credit
Agreement").
         In accordance with the terms of the Credit Documents and the Midstream
Guaranty (collectively, the "Security Documents"), the Subsidiary hereby (a)
joins the Midstream Guaranty as a party thereto and assumes all the obligations
of a Guarantor thereunder, (b) agrees to be bound by the provisions of the
Midstream Guaranty as if the Subsidiary had been an original party to the
Midstream Guaranty, and (c) confirms that, after joining the Midstream Guaranty
as set forth above, the representations and warranties set forth in each of the
Credit Documents with respect to the Subsidiary are true and correct in all
material respects as of the date of this Joinder Agreement.
         For purposes of notices under the Security Documents, the notice
address for the Subsidiary may be given to the Subsidiary by providing notice
addressed to [Subsidiary' Name] c/o The ▇▇▇▇▇▇▇▇ Companies, Inc., in any manner
that notice is permitted to be given to the Company pursuant to the terms of the
Credit Agreement.
         THIS WRITTEN AGREEMENT AND THE CREDIT DOCUMENTS REPRESENT THE FINAL
AGREEMENT AMONG THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES.
         THERE ARE NO UNWRITTEN ORAL AGREEMENTS AMONG THE PARTIES.
                                      -4-
         IN WITNESS WHEREOF this Joinder Agreement is executed and delivered as
of the ___ day of ____________, _____.
                                    [Joining Subsidiary]
                                    By:
                                       --------------------------------------
                                    Name:
                                         ------------------------------------
                                    Title:
                                          -----------------------------------