**Exhibit 10.A****FIRST AMENDMENT TO CREDIT AGREEMENT**     THIS FIRST AMENDMENT (herein called this “Amendment”) dated as of March 27, 2006, isamong EL PASO EXPLORATION & PRODUCTION COMPANY (formerly El Paso Production Holding Company), ELPASO PRODUCTION COMPANY, and EL PASO E&P COMPANY, L.P. (formerly El Paso Production Oil & Gas USA,L.P.) (individually, a “Borrower” and collectively, the “Borrowers”), and FORTISCAPITAL CORP. (“Fortis”), as administrative agent for the Lenders (“Administrative“Agent”) for the Lenders party to the Credit Agreement (as defined below).**W I T N E S S E T H :**     WHEREAS, El Paso Production Holding Company, El Paso Production Company, El Paso Energy RatonCorporation, El Paso Production GOM Inc. (collectively, the “Original Borrowers”), theAdministrative Agent and the Lenders entered into that certain Amended and Restated CreditAgreement dated as of October 19, 2005 (the “Credit Agreement”), for the purposes andconsideration therein expressed, pursuant to which the Lenders became obligated to make loans andissue letters of credit to the Borrowers as therein provided;     WHEREAS, pursuant to a reorganization plan implemented by El Paso Corporation on or aboutDecember 31, 2005, (i) the outstanding equity interests of El Paso Production Oil & Gas Company, ElPaso Production Oil & Gas Holdings, Inc., El Paso Production Resale Company, El Paso Production Oil& Gas USA, L.P., El Paso Energy Oil Transmission, L.L.C. and El Paso Production Oil & GasGathering, L.P. were transferred, directly or indirectly, to El Paso Production Holding Company,(ii) El Paso Production GOM Inc. and El Paso Energy Raton Corporation merged into El PasoProduction Oil & Gas USA, L.P., which thereby became a Borrower under the Credit Agreement, (iii)the name of El Paso Production Holding Company was changed to El Paso Exploration & ProductionCompany, (iv) the name of El Paso Production Oil & Gas USA, L.P. was changed to El Paso E&PCompany, L.P. and (v) the names of certain of the Guarantors were changed;     WHEREAS, the Borrowers have requested that the Administrative Agent and the Lenders amend theCredit Agreement as set forth herein; and     WHEREAS, the Administrative Agent and the Lenders are willing to amend the Credit Agreement onthe terms and subject to the conditions set forth herein;     NOW, THEREFORE, in consideration of the premises and the mutual covenants and agreementscontained herein and in the Credit Agreement, in consideration of the loans and letters of creditwhich may hereafter be made or issued by the Lenders to the Borrowers, and for other good andvaluable consideration, the receipt and sufficiency of which are hereby acknowledged, the partieshereto do hereby agree as follows:
 

 
     1. Terms Defined in the Credit Agreement. Unless the context otherwise requires orunless otherwise expressly defined herein, the terms defined in the Credit Agreement shall have thesame meanings whenever used in this Amendment.     2. Amendments. The Credit Agreement is hereby amended as set forth below in thisSection 2:     (a) Section 1.1 of the Credit Agreement is hereby amended by deleting the defined term“EPPHC”- El Paso Production Holding Company.     (b) Section 1.1 of the Credit Agreement is hereby amended by adding the defined term“EPEP”- El Paso Exploration & Production Company.     (c) The Credit Agreement is hereby amended by deleting each reference to the term“EPPHC” and replacing it with the term “EPEP”.     (d) Section 8.7(c) of the Credit Agreement is hereby amended to read as follows:     ”(c) provided no Default, Event of Default, Borrowing Base Deficiencyor Collateral Value Deficiency shall have occurred and be continuing, EPEPmay declare and pay dividends or make other distributions of property withrespect to any fiscal year (but no later than (A) December 31, 2006, withrespect to the fiscal year ended December 31, 2005, and (B) 120 days afterthe end of each other fiscal year) in an amount that does not exceed the sumof (i) the Available Distribution Amount, plus (ii) the net proceeds of anyequity offering or contribution of equity, in each case received by a LoanParty during such fiscal year, plus (iii) 100% of Free Cash Flow of the LoanParties accrued during such fiscal year, minus (iv) Free Cash Flow andcapital contributions used to repay Indebtedness pursuant to Section8.9(z).”     (e) Section 8.8(h) of the Credit Agreement is hereby amended to read as follows:     ”(h) provided no Default, Event of Default, Borrowing Base Deficiency,or Collateral Value Deficiency shall have occurred and is continuing,additional loans or advances made on a revolving basis to El PasoCorporation under the Cash Management Program up to a maximum outstandingamount of $200,000,000; and”.     (f) Section 8.9(y) of the Credit Agreement is hereby amended to read as follows:     ”(y) provided no Default, Event of Default, Borrowing Base Deficiencyor Collateral Value Deficiency shall have occurred and be continuing, payprincipal with respect to and interest on Indebtedness owed to El PasoCorporation; provided, however, that such Indebtedness
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was incurred on a revolving basis and the amount of such revolvingIndebtedness outstanding at any time does not exceed $200,000,000; and”.     3. Effective Date. This Amendment shall become effective (the “EffectiveDate”) when the Lenders shall have received, at the Administrative Agent’s office:     (i) A counterpart of this Amendment executed and delivered by Borrowers;     (ii) A confirmation of guaranty from the Guarantors; and     (iii) A certificate of a duly authorized officer of each Borrower to the effectthat all of the representations and warranties set forth in Section 4 hereof aretrue and correct at and as of the time of such effectiveness and that there existsno Default or Event of Default under the Credit Agreement.     4. Representations and Warranties of Borrowers. In order to induce the Lenders toenter into this Amendment, each of the Borrowers represents and warrants to Lenders that:     (i) The representations and warranties contained in Section 5 of the CreditAgreement are true and correct at and as of the time of the effectiveness hereof.     (ii) Such Borrower is authorized to execute and deliver this Amendment and suchBorrower is and will continue to be duly authorized to borrow and to perform itsobligations under the Credit Agreement. Such Borrower has duly taken all actionnecessary to authorize the execution and delivery of this Amendment and to authorizethe performance of the obligations of such Borrower hereunder.     (iii) The execution and delivery by such Borrower of this Amendment, theperformance by such Borrower of its obligations hereunder and the consummation ofthe transactions contemplated hereby do not and will not conflict with anyprovisions of law, statute, rule or regulation or of the certificate ofincorporation and bylaws or certificate of limited partnership and agreement oflimited partnership, as applicable, of such Borrower, or of any material agreement,judgment, license, order or permit applicable to or binding upon such Borrower, orresult in the creation of any lien, charge or encumbrance upon any assets orproperties of such Borrower. Except for those which have been duly obtained, noconsent, approval, authorization or order of any court or governmental authority orthird party is required in connection with the execution and delivery by suchBorrower of this Amendment or to consummate the transactions contemplated hereby.     (iv) When duly executed and delivered, each of this Amendment and the CreditAgreement will be a legal and binding instrument and agreement of such Borrower,enforceable in accordance with their terms, except as limited by
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bankruptcy, insolvency and similar laws applying to creditors’ rights generallyand by principles of equity applying to creditors’ rights generally.     5. Ratification of Agreements. The Credit Agreement is hereby ratified and confirmedin all respects. The execution, delivery and effectiveness of this Amendment shall not, except asexpressly provided herein, operate as a waiver of any right, power or remedy of the Lenders underthe Credit Agreement or any other Loan Document nor constitute a waiver of any provision of theCredit Agreement or any other Loan Document.     6. Survival of Agreements. All representations, warranties, covenants and agreementsof the Borrowers herein shall survive the execution and delivery of this Amendment and theperformance hereof, and shall further survive until all of the Obligations are paid in full. Allrepresentations, warranties, acknowledgements and agreements contained in Section 5 of the CreditAgreement are hereby reconfirmed on and as of the date hereof. All statements and agreementscontained in any certificate or instrument delivered by any Borrower hereunder or under the CreditAgreement to Lenders shall be deemed to constitute representations and warranties by, or agreementsand covenants of, such Borrower under this Amendment and under the Credit Agreement.     7. Loan Documents. This Amendment is a Loan Document, and all provisions in theCredit Agreement pertaining to Loan Documents apply hereto.     8. Governing Law. This Amendment shall be governed by and construed in accordancewith the laws of the State of New York and any applicable laws of the United States of America inall respects, including construction, validity and performance.     9. Counterparts. This Amendment may be separately executed in counterparts and by thedifferent parties hereto in separate counterparts, each of which when so executed shall be deemedto constitute one and the same Amendment.     10. **THIS AMENDMENT AND THE OTHER LOAN DOCUMENTS REPRESENT THE FINAL AGREEMENT BETWEEN THEPARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORALAGREEMENT OF THE PARTIES.*****[The Remainder of this Page Intentionally Left Blank]***
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     IN WITNESS WHEREOF, this Amendment is executed as of the date first above written.      **EL PASO EXPLORATION & PRODUCTION COMPANY**