1

 
          NOW, THEREFORE, in consideration of the premises and the mutual covenants herein contained,the parties hereto agree as follows:          **I.**           **Amendment to Section 10.4 of U.S. Credit Agreement**.   In reliance on therepresentations and warranties of the U.S. Borrower and the Canadian Borrower contained herein, andsubject to the terms, and satisfaction of the conditions precedent, set forth in SectionVIII hereof, Section 10.4 of the U.S. Credit Agreement shall be amended effective as of theEffective Date to (a) delete the reference to “U.S.$5,000,000” set forth in clause (b)(iii) ofSection 10.4 of the U.S. Credit Agreement and replace it with “U.S.$2,500,000 unless each of theBorrower (unless an Event of Default has occurred and is continuing) and the Global AdministrativeAgent otherwise consent”, (b) delete the reference to “U.S.$5,000,000” set forth in clause (b)(vii)of Section 10.4 of the U.S. Credit Agreement and replace it with “U.S.$2,500,000”, and (c) insert“(unless an Event of Default has occurred and is continuing)” after the reference to “Borrower” inclause (b)(vii) of Section 10.4 of the U.S. Credit Agreement.          **II.**          **Amendment to Section 10.4 of Canadian Credit Agreement**.   In reliance on therepresentations and warranties of the U.S. Borrower and the Canadian Borrower contained herein, andsubject to the terms, and satisfaction of the conditions precedent, set forth in SectionVIII hereof, Section 10.4 of the Canadian Credit Agreement shall be amended effective as of theEffective Date to (a) delete the reference to “U.S.$5,000,000” set forth in clause (b)(iii) ofSection 10.4 of the Canadian Credit Agreement and replace it with “U.S.$2,500,000 unless each ofthe Borrower (unless an Event of Default has occurred and is continuing) and the GlobalAdministrative Agent otherwise consent”, (b) delete the reference to “U.S.$5,000,000” set forth inclause (b)(vii) of Section 10.4 of the Canadian Credit Agreement and replace it with“U.S.$2,500,000”, and (c) insert “(unless an Event of Default has occurred and is continuing)”after the reference to “Borrower” in clause (b)(vii) of Section 10.4 of the Canadian CreditAgreement.          **III.**          **Amendment to Schedule 2.1 of U.S. Credit Agreement**.   In reliance on therepresentations and warranties of the U.S. Borrower and the Canadian Borrower contained herein, andsubject to the terms, and satisfaction of the conditions precedent, set forth in SectionVIII hereof, Schedule 2.1 to the U.S. Credit Agreement shall be deleted in its entirety andSchedule 2.1 – U.S. Credit Agreement attached to this Amendment shall be substituted in lieuthereof, effective as of the Effective Date.          **IV.**          **Amendment to Schedule 2.1 of Canadian Credit Agreement**.   In reliance on therepresentations and warranties of the U.S. Borrower and the Canadian Borrower contained herein, andsubject to the terms, and satisfaction of the conditions precedent, set forth in SectionVIII hereof, Schedule 2.1 to the Canadian Credit Agreement shall be deleted in its entirety andSchedule 2.1 – Canadian Credit Agreement attached to this Amendment shall be substituted in lieuthereof, effective as of the Effective Date.          **V.**           **Joinder of New U.S. Lenders**.   Effective as of the Effective Date, each New U.S.Lender hereby joins in, becomes a party to, and agrees to comply with and be bound by the terms andconditions of the U.S. Credit Agreement as a Lender thereunder and under each and every other LoanDocument to which any U.S. Lender is required to be bound by the U.S. Credit Agreement, to the sameextent as if such New U.S. Lender were an original signatory thereto.
2

 
         **VI.**          **Global Borrowing Base**.          A.          Subject to adjustments pursuant to Sections 2.8(d), (e), (g), and (h) of the U.S. CreditAgreement or Sections 2.7(d), (e), (g), and (h) of the Canadian Credit Agreement, by execution ofthis Amendment, each of the Global Administrative Agent, the Combined Lenders, the U.S. Borrowerand the Canadian Borrower agree during the period from the date hereof to the date of the nextredetermination of the Global Borrowing Base (as defined in each of the Combined Credit Agreements)pursuant to the provisions of Section 2.8 of the U.S. Credit Agreement or Section 2.7 of theCanadian Credit Agreement that (a) the Global Borrowing Base (as defined in each of the CombinedCredit Agreements) shall equal U.S.$1,200,000,000, (b) the U.S. Borrowing Base shall equalU.S.$915,000,000, (c) the Allocated U.S. Borrowing Base (as defined in each of the Combined CreditAgreements) shall equal U.S.$800,000,000, and (d) the Allocated Canadian Borrowing Base (as definedin each of the Combined Credit Agreements) shall equal U.S.$400,000,000.          B.          Each of the Global Administrative Agent, the Combined Lenders, the U.S. Lenders, the U.S.Borrower and the Canadian Borrower agree and acknowledge that (a) the determination of the GlobalBorrowing Base (as defined in each of the Combined Credit Agreements) and U.S. Borrowing Base setforth in Section VI(A) of this Amendment is not a Scheduled Redetermination of the GlobalBorrowing Base (as defined in each of the Combined Credit Agreements) and the U.S. Borrowing Basepursuant to Section 2.8(b) of the U.S. Credit Agreement or Section 2.7(b) of the Canadian CreditAgreement and (b) such determination of the Global Borrowing Base (as defined in each of theCombined Credit Agreements) and the U.S. Borrowing Base shall not be considered as a request for a“discretionary determination” of the Global Borrowing Base (as defined in each of the CombinedCredit Agreements) and the U.S. Borrowing Base by the Borrower, the Global Administrative Agent orthe Required Lenders for the purposes of Section 2.8(e) of the U.S. Credit Agreement or Section2.7(e) of the Canadian Credit Agreement.          C.          In accordance with Section 2.1(c) of each of the U.S. Credit Agreement and the CanadianCredit Agreement, the Global Administrative Agent hereby notifies the Canadian AdministrativeAgent, the Combined Lenders, the U.S. Borrower and the Canadian Borrower of the reallocation of theGlobal Commitments under the Combined Credit Agreements as set forth and described on Schedule 2.1– U.S. Credit Agreement and Schedule 2.1 – Canadian Credit Agreement attached hereto.          **VII.**       **Rearrangement of Existing Loans**.   Upon the effectiveness of this Amendment:          A.          All of the Combined Commitments and outstanding Combined Obligations under the CombinedCredit Agreements as of the date of such effectiveness shall hereby be restructured, rearranged,renewed, extended and continued under the applicable Combined CreditAgreement (as amended hereby) and all Combined Loans and Letters of Credit (as defined in eachof the Combined Credit Agreements) outstanding under the applicable Combined Credit Agreement as ofthe date of such effectiveness shall hereby become Combined Loans and Letters of Credit (as definedin each of the Combined Credit Agreements) outstanding under the applicable Combined CreditAgreement (as amended hereby).
3

 
          B.          In connection herewith, the Combined Lenders party to the Combined Credit Agreements priorto the effectiveness of this Amendment (the “**Existing Lenders**”) hereby sell, assign,transfer and convey, and the Combined Lenders hereby purchase and accept, so much of the aggregateCombined Commitments under, Combined Loans outstanding under, and participations in Letters ofCredit (as defined in each of the Combined Credit Agreements) issued pursuant to, the CombinedCredit Agreements such that the Combined Commitment of each Combined Lender shall be as set forthon Schedule 2.1 to each of the Combined Credit Agreements (as amended hereby).   The foregoingassignments, transfers and conveyances are without recourse to the Existing Lenders and without anywarranties whatsoever by any Agent, any Issuing Bank or any Existing Lender as to title,enforceability, collectability, documentation or freedom from liens or encumbrances, in whole or inpart, other than the warranty of each Existing Lender that it has not previously sold, transferred,conveyed or encumbered such interests.          **VIII.**      **Effectiveness**.   This Amendment shall become effective as of the date that eachof the following conditions precedent have been satisfied (the “**Effective Date**”):          A.          The Global Administrative Agent shall have received counterparts hereof duly executed bythe U.S. Borrower, the Canadian Borrower, the Global Administrative Agent, the CanadianAdministrative Agent, each Combined Lender whose Commitment is increasing hereunder, each New U.S.Lender, the Supermajority Lenders and the U.S. Supermajority Lenders (or, in the case of any partyas to which an executed counterpart shall not have been received, telegraphic, telex, or otherwritten confirmation from such party of execution of a counterpart hereof by such party).          B.          The Combined Borrowers shall have paid (i) all reasonable out-of-pocket fees and expensesof counsel for the Global Administrative Agent incurred, to the extent the same have been invoicedand sent to the U.S. Borrower at least two (2) Business Days prior to the Effective Date, includingall such out-of-pocket fees and expenses incurred in connection with the preparation, negotiationand execution of this Amendment and any other Combined Loan Documents to be executed and deliveredin connection therewith and (ii) any and all fees payable to Global Administrative Agent or certainCombined Lenders pursuant to or in connection with this Amendment in consideration for theagreements set forth herein.          C.          Each Combined Lender that is a New U.S. Lender or whose Global Commitment is increasinghereunder that has requested a Note shall have received a duly completed and executed Note, payableto the order of such Combined Lender.          D.          If, on the Effective Date, any Eurodollar Borrowings are outstanding under the CombinedCredit Agreements and if the Effective Date is not the last day of the Interest Period(s) inrespect of such Eurodollar Borrowings, the Combined Borrowers shall have paid anycompensation required under Section 2.17 of the U.S. Credit Agreement and Section 2.16 of theCanadian Credit Agreement.          E.          No Default, Event of Default, Global Borrowing Base Deficiency or U.S. Borrowing BaseDeficiency shall have occurred which is continuing.
4

 
          **IX.**       **Reaffirmation of Representations and Warranties**.   To induce the Combined Lendersand the Global Administrative Agent to enter into this Amendment, the U.S. Borrower and theCanadian Borrower hereby reaffirm, as of the date hereof, the following:                    (i)           The representations and warranties of each Loan Party (as such term is defined inthe U.S. Credit Agreement and the Canadian Credit Agreement, collectively, the “**CombinedLoan Parties**”) set forth in the Combined Loan Documents to which it is a party are trueand correct on and as of the date hereof (or, if stated to have been made expressly as of anearlier date, were true and correct in all material respects as of such date and, except tothe extent waived in writing by the Combined Lenders, the Required Lenders, the MajorityLenders, the U.S. Lenders or the U.S. Required Lenders, as applicable).                    (ii)           Each of the Combined Loan Parties (a) is a corporation or limited partnership dulyincorporated or organized (as applicable), validly existing and in good standing under thelaws of its jurisdiction of incorporation or organization, (b) has all corporate or limitedpartnership power (as applicable) and all material governmental licenses, authorizations,consents and approvals required to carry on its businesses as now conducted and as proposedto be conducted, and (c) is duly qualified to transact business as a foreign corporation orlimited partnership in each jurisdiction where a failure to be so qualified would reasonablybe expected to have a Material Adverse Effect.                    (iii)           The execution, delivery and performance of this Amendment and the other CombinedLoan Documents by each Combined Loan Party (to the extent each Combined Loan Party is aparty to this Amendment and such Combined Loan Documents) (a) are within such Combined LoanParty’s corporate or limited partnership powers, (b) when executed will be duly authorizedby all necessary corporate or limited partnership action, (c) require no action by or inrespect of, or filing with, any Governmental Authority (other than (1) actions or filingspursuant to the Exchange Act and (2) actions or filings that have been taken or made and arein full force and effect) and (d) do not contravene, or constitute a default under, anyprovision of applicable Governmental Rule (including, without limitation, Regulation U) orof the articles or certificate of incorporation, bylaws, regulations, partnership agreementor comparable charter documents of any Combined Loan Party or of any agreement, judgment,injunction, order, decree or other instrument binding upon any Combined Loan Party or resultin the creation or imposition of any Lien on any Borrowing Base Property or Collateral otherthan the Liens securing the Combined Obligations.                    (iv)           This Amendment and each other Combined Loan Document constitutes, or when executedand delivered will constitute, valid and binding obligations of each Combined Loan Partywhich is a party thereto, enforceable against each suchCombined Loan Party which executes the same in accordance with its terms except as theenforceability thereof may be limited by (a) bankruptcy, insolvency, reorganization,moratorium, or similar Governmental Rules affecting creditors’ rights generally, and (b)equitable principles of general applicability (whether enforcement is sought by proceedingsat law or in equity).
5

 
                    (v)          Neither a Default nor an Event of Default has occurred and will exist under eitherCombined Credit Agreement after giving effect to the transactions contemplated by, and theamendments contained in, this Amendment or the other Combined Loan Documents.   Neither theU.S. Borrower or any of its Subsidiaries nor the Canadian Borrower or any of itsSubsidiaries is in default under, nor has any event or circumstance occurred which, but forthe expiration of any applicable grace period or the giving of notice, or both, wouldconstitute a default under, any Material Agreement to which the U.S. Borrower or any of itsSubsidiaries or the Canadian Borrower or any of its Subsidiaries is a party or by which theU.S. Borrower or any of its Subsidiaries or the Canadian Borrower or any of its Subsidiariesis bound which default would reasonably be expected to have a Material Adverse Effect.   TheU.S. Borrower is in compliance with the financial covenants set forth in Article VI of theU.S. Credit Agreement.                    (vi)          No event or events have occurred since December 31, 2007 which individually or inthe aggregate would reasonably be expected to have a Material Adverse Effect.          **X.**          **Representations and Warranties of New U.S. Lenders**.   Each New U.S. Lender (i)represents and warrants that (a) it has full power and authority, and has taken all actionnecessary, to execute and deliver this Amendment, to consummate the transactions contemplatedhereby and to become a Lender under the U.S. Credit Agreement, (b) from and after the EffectiveDate, it shall be bound by the provisions of the U.S. Credit Agreement as a Lender thereunder, (c)it has received a copy of the U.S. Credit Agreement, together with copies of the most recentfinancial statements delivered pursuant to Section 5.1 thereof, and such other documents andinformation as it has deemed appropriate to make its own credit analysis and decision to enter intothis Amendment and to become a Lender on the basis of which it has made such analysis and decisionindependently and without reliance on the Global Administrative Agent or any other U.S. Lender, and(d) if it is a Foreign Lender, attached hereto is any documentation required to be delivered by itpursuant to the terms of the U.S. Credit Agreement, duly completed and executed by the New U.S.Lender; and (ii) agrees that (a) it will, independently and without reliance on the GlobalAdministrative Agent or any other U.S. Lender, and based on such documents and information as itshall deem appropriate at the time, continue to make its own credit decisions in taking or nottaking action under the Loan Documents, and (b) it will perform in accordance with their terms allof the obligations which by the terms of the Loan Documents are required to be performed by it as aLender.         **XI.**          **Defined Terms**.   Capitalized terms used herein when defined in the U.S. CreditAgreement (including, to the extent applicable, after giving effect to this Amendment) shall havethe same meanings herein unless the context otherwise requires.         **XII.**         **Reaffirmation of Combined Credit Agreements**.   This Amendment shall be deemed tobe an amendment to the Combined Credit Agreements, and the Combined Credit Agreements, as amendedhereby, are hereby ratified, approved and confirmed in each and every respect.   All references tothe Combined Credit Agreements herein and in any other document, instrument, agreement or writingshall hereafter be deemed to refer to the Combined Credit Agreements as amended hereby.
6

 
          **XIII.**          **Governing Law**.   **THIS AMENDMENT SHALL BE CONSTRUED IN ACCORDANCE WITH THE LAWS OFTHE STATE OF TEXAS.**           **NOTWITHSTANDING THE FOREGOING SENTENCE AND AFTER GIVING EFFECT TO THE TEXTUAL AMENDMENTSCONTAINED IN****SECTIONS I****,****II****,****III****AND****IV****OF THIS AMENDMENT, (i) THEU.S. CREDIT AGREEMENT (AS AMENDED HEREBY) SHALL CONTINUE TO BE GOVERNED BY, AND CONSTRUED INACCORDANCE WITH, THE LAW SPECIFIED IN SECTION 10.9(a) OF THE U.S. CREDIT AGREEMENT, AND (ii) THECANADIAN CREDIT AGREEMENT (AS AMENDED HEREBY) SHALL CONTINUE TO BE GOVERNED BY, AND CONSTRUED INACCORDANCE WITH, THE LAW SPECIFIED IN SECTION 10.9(a) OF THE CANADIAN CREDIT AGREEMENT.**          **XIV.**          **Severability of Provisions**.   Any provision of this Amendment held to be invalid,illegal or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to theextent of such invalidity, illegality or unenforceability without affecting the validity, legalityand enforceability of the remaining provisions hereof; and the invalidity of a particular provisionin a particular jurisdiction shall not invalidate such provision in any other jurisdiction.          **XV.**            **Counterparts**.   This Amendment may be executed in counterparts (and by differentparties hereto on different counterparts), each of which shall constitute an original, but all ofwhich when taken together shall constitute a single contract.   Delivery of an executed counterpartof a signature page of this Amendment by telecopy (or other electronic transmission acceptable tothe Global Administrative Agent) shall be effective as delivery of a manually executed counterpartof this Amendment.          **XVI.**          **Headings**.   Article and Section headings used herein are for convenience ofreference only, are not part of this Amendment and shall not affect the construction of, or betaken into consideration in interpreting, this Amendment.          **XVII.**        **Successors and Assigns**.   This Amendment shall be binding upon and inure to thebenefit of the parties hereto and their respective successors and assigns permitted hereby(including any Affiliate of an Issuing Bank that issues any Letter of Credit), except that neitherthe U.S. Borrower nor the Canadian Borrower may assign or otherwise transfer any of its rights orobligations hereunder without the prior written consent of the Global Administrative Agent, eachIssuing Bank and each Combined Lender (and any attempted assignment or transfer by either the U.S.Borrower or the Canadian Borrower without such consent shall be null and void).         **XVIII.**        **No Oral Agreements**.   **THIS AMENDMENT, THE COMBINED CREDIT AGREEMENTS, AS AMENDEDHEREBY, AND THE OTHER COMBINED LOANDOCUMENTS REPRESENT THE FINAL AGREEMENT BETWEEN AND AMONG THE PARTIES WITH RESPECT TO THESUBJECT MATTER HEREOF AND THEREOF AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES.   THERE ARE NO UNWRITTEN ORALAGREEMENTS AMONG THE PARTIES.**
7

 
          **XIX.**          **Loan Document****.   This Amendment constitutes a “Loan Document,” a “Canadian LoanDocument” and a “Combined Loan Document” under and as defined in the U.S. Credit Agreement, and a“Loan Document,” a “U.S. Loan Document” and a “Combined Loan Document” under and as defined in theCanadian Credit Agreement.***[Signature Pages to Follow]*
8

 
          IN WITNESS WHEREOF, the U.S. Borrower, the Canadian Borrower, the undersigned CombinedLenders, the Global Administrative Agent and the Canadian Administrative Agent have executed thisAmendment as of the date first above written.       **U.S. BORROWER**       **QUICKSILVER RESOURCES INC.,**a Delaware corporation, as U.S. Borrower       By: /s/ MarLu Hiller       MarLu Hiller, Vice President – Treasurer       **CANADIAN BORROWER**       **QUICKSILVER RESOURCES CANADA INC.**,an Alberta, Canada corporation, as Canadian Borrower       By: /s/ MarLu Hiller       MarLu Hiller, Vice President – TreasurerEach of the undersigned (i) acknowledge, consent and agree to this Amendment and each of the termsand provisions contained herein, and (ii) agree that the Combined Loan Documents (as amendedhereby) to which it is a party shall remain in full force and effect and shall continue to be thelegal, valid and binding obligation of such Person, enforceable against it in accordance with itsterms.       **ACKNOWLEDGED, CONSENTED AND AGREED TO**as of the date first above written:       **COWTOWN GAS PROCESSING L.P.**,a Texas limited partnership       By: Cowtown Pipeline Management, Inc.,its general partner       By: /s/ MarLu Hiller     Name: MarLu Hiller  Title: Vice President – Treasurer [Signature Page]