Exhibit 4.C


    EXHIBIT
      4.C

    

      


       

      
        

        

      

       

      


      


       

      


       

      


       

      


       

      


       

      EL
        PASO
        NATURAL GAS COMPANY

      Company

      and

      WILMINGTON
        TRUST COMPANY

      Trustee

       

      First
        Supplemental Indenture

      


      Dated
        as of
        April 4, 2007

      _________________

       

      7
5⁄8%
        Notes
        due 2010

      


      Supplementing
        the
        Indenture, dated as of July 21, 2003, between El Paso Natural Gas Company,
        as
        the Company, and Wilmington Trust Company, as Trustee.

       

      


      
 

       

      


       

      


       

      


       

      


       

       

      
        

        

      

      


      


       


      THIS
        FIRST
        SUPPLEMENTAL INDENTURE (this “First Supplemental Indenture”), dated as of April
        4, 2007, between EL PASO NATURAL GAS COMPANY, a Delaware corporation (the
        “Company”), and WILMINGTON TRUST COMPANY, a Delaware banking corporation, as
        Trustee (the “Trustee”), under the Indenture, dated as of July 21, 2003 (the
“Indenture”). Capitalized terms used herein and not otherwise defined shall have
        the meaning assigned to them in the Indenture.

       

       

      WITNESSETH:
        

       

      WHEREAS,
        the
        Company has issued its 75⁄8% Notes due 2010 (the “Notes”) pursuant to the
        Indenture;

       

      WHEREAS,
        the
        Company has offered to purchase for cash any and all outstanding Notes (the
        “Tender Offer”);

       

      WHEREAS,
        in
        connection with the Tender Offer, the Company has requested that Holders
        of the
        Notes deliver their consents with respect to the deletion of certain provisions
        of the Indenture;

       

      WHEREAS,
        Section
        8.02 of the Indenture provides that the Company and the Trustee may amend
        or
        supplement the Indenture and the Notes may be amended or supplemented with
        the
        consent of the Holders of a majority in principal amount of the Notes then
        outstanding (including, without limitation, consents obtained in connection
        with
        a purchase of, or tender offer or exchange offer for, the Notes);

       

      WHEREAS,
        the
        Holders of a majority of the principal amount of the Notes outstanding have
        duly
        consented to the proposed modifications set forth in this First Supplemental
        Indenture in accordance with Section 8.02 of the Indenture;

       

      WHEREAS,
        the
        Company has heretofore delivered or is delivering contemporaneously herewith
        to
        the Trustee (i) a copy of resolutions of the Board of Directors of the Company
        authorizing the execution of this First Supplemental Indenture, (ii) evidence
        of
        the written consent of the Holders set forth in the immediately preceding
        paragraph and (iii) the Officers’ Certificate and the Opinion of Counsel
        described in Section 8.06 of the Indenture; and

       

      WHEREAS,
        all
        conditions necessary to authorize the execution and delivery of this First
        Supplemental Indenture and to make this First Supplemental Indenture valid
        and
        binding have been complied with or have been done or performed.

       

      NOW,
        THEREFORE, in
        consideration of the foregoing and notwithstanding any provision of the
        Indenture which, absent this First Supplemental Indenture, might operate
        to
        limit such action, the parties hereto, intending to be legally bound hereby,
        agree as follows:

       

      ARTICLE
        ONE

       

      Amendments

       

      Section
        1.01 Amendments.

       

      (a) Subject
        to Section
        2.01 hereof, the Indenture is hereby amended by deleting the following
        provisions of the Indenture, in their respective entireties: Section 3.04,
        Section 3.05, Section 3.06, Section 3.07, Section 3.08, Section 3.09, Section
        3.10, Section 3.11, Article IV, clauses (d), (e) and (f) of Section 5.01,
        Section 7.03 and clauses (c)(ii) and (f) of Section 7.04.

       

      (b) Section
        3.03 is
        hereby amended and restated to read, in its entirety, as follows:

       

      “Section
        3.03 Trust
        Indenture
        Act.

       

      The
        Company shall
        at all times comply with TIA Section 3.14(a).”

       

      (c) Effective
        as of the
        date hereof, none of the Company, the Trustee or other parties to or
        beneficiaries of the Indenture shall have any rights, obligations or liabilities
        under such Sections or Article, and such Sections or Article shall not be
        considered in determining whether an Event of Default has occurred or whether
        the Company has observed, performed or complied with the provisions of the
        Indenture.

       

      Section
        1.02 Amendment
        of
        Definitions.
        The Indenture is
        hereby amended by deleting any definitions from the Indenture with respect
        to
        which references would be eliminated as a result of the amendments to the
        Indenture pursuant to Section 1.01 hereof.

       

      ARTICLE
        TWO

       

      Miscellaneous

       

      Section
        2.01 Effect
        of
        Supplemental Indenture.
        Except as amended
        hereby, all of the terms of the Indenture shall remain and continue in full
        force and effect and are hereby confirmed in all respects. From and after
        the
        date of this First Supplemental Indenture, all references to the Indenture
        (whether in the Indenture or in any other agreements, documents or instruments)
        shall be deemed to be references to the Indenture as amended and supplemented
        by
        this First Supplemental Indenture. On and not prior to the date on which
        tendered Notes representing a majority of the Notes outstanding are accepted
        for
        purchase pursuant to the Tender Offer, this First Supplemental Indenture
        will
        become operative; provided,
        however,
        that if and only
        if this First Supplemental Indenture becomes operative, the provisions hereof
        shall be deemed effective as of the date hereof.

       

      Section
        2.02 Governing
        Law.
        THE LAWS OF THE
        STATE OF NEW YORK SHALL GOVERN AND BE USED TO CONSTRUE THIS FIRST SUPPLEMENTAL
        INDENTURE.

       

      Section
        2.03 No
        Representations by Trustee.
        The recitals
        contained herein shall be taken as the statement of the Company, and the
        Trustee
        assumes no responsibility for the correctness or completeness of the same.
        The
        Trustee makes no representation as to the validity or sufficiency of this
        First
        Supplemental Indenture.

       

      Section
        2.04
Certain
        Duties
        and Responsibilities of the Trustee.
        In entering into
        this First Supplemental Indenture, the Trustee shall be entitled to the benefit
        of every provision of the Indenture relating to the conduct or affecting
        the
        liability or affording protection to the Trustee, whether or not elsewhere
        herein so provided.

       

      Section
        2.05
Endorsement
        and
        Change of Form of Notes.
        Any Notes
        authenticated and delivered after the close of business on the date that
        this
        First Supplemental Indenture becomes effective shall be affixed to, stamped,
        imprinted or otherwise legended by the Trustee, with a notation as
        follows:

       

      “Effective
        as of
        April 4, 2007, certain restrictive covenants of the Company and certain of
        the
        Events of Default have been eliminated, as provided in the First Supplemental
        Indenture, dated as of April 4, 2007. Reference is hereby made to said First
        Supplemental Indenture, copies of which are on file with the Trustee, for
        a
        description of the amendments made therein.” 

       

      Section
        2.06 Counterparts.
        This First
        Supplemental Indenture may be executed in any number of counterparts, each
        of
        which shall be an original; but such counterparts shall constitute but one
        and
        the same instrument.

       

      (signature
        page
        follows)

       


      
        
          
          

        

        
          
          

          
            

          

        

        
          
          

        

      


      IN
        WITNESS WHEREOF,
        the parties hereto have caused this First Supplemental Indenture to be duly
        executed all as of the date hereof. 

       

      

        
          	
                  EL
                    PASO
                    NATURAL GAS COMPANY 

                
	 
	 
	 
	
                  By:

                	
                  /s/
                    John J.
                    Hopper

                
	 	
                  John
                    J.
                    Hopper

                
	 	
                  Vice
                    President and Secretary

                


        

        


        


        
          	
                  WILMINGTON
                    TRUST COMPANY,

                  as
                    Trustee

                
	 
	 
	 
	
                  By:

                	
                  /s/
                    Kristin
                    L. Moore

                
	 	
                  Name:

                	
                  Kristin
                    L.
                    Moore

                
	 	
                  Title:

                	
                  Senior
                    Financial Services Officer