exhibit4a.htm


    Exhibit
      4.A

     

    
      

    


     

    COLORADO
      INTERSTATE GAS COMPANY

     

    


     

    as
      Issuer

     

    


     

    and

     

    


     

    THE
      BANK OF
      NEW YORK TRUST COMPANY, N.A.

     

    


     

    as
      Trustee

     

    


     

    FOURTH
      SUPPLEMENTAL INDENTURE

     

    


     

    Dated
      as of
      October 15, 2007

     

    


     

    To

     

    


     

    INDENTURE

     

    


     

    Dated
      as of
      June 27, 1997

     

    
       

      
        
          
          

        

        
          
          

          
            

          

        

        
          
          

        

      






    TABLE
      OF
      CONTENTS

     

    
 

    
      	 	
              Page

            
	
              ARTICLE
                1 Relation to Indenture;
                Definitions 

            	
              1

            
	
              SECTION
                1.01.
                Relation to Indenture. 

            	
              1

            
	
              SECTION
                1.02.
                Definitions. 

            	
              1

            
	
              SECTION
                1.03.
                General References. 

            	
              1

            
	
               

            	 
	
              ARTICLE
                2
                Amendments to Original Indenture 

            	
              1

            
	
              SECTION
                2.01.
                Legal Existence. 

            	
              1

            
	
              SECTION
                2.02.
                When Company May Merge, Etc.

            	
              2

            
	
              SECTION
                2.03.
                Amendments, Supplements and Waivers Without Consent of
                Holders

            	
              2

            
	
              SECTION
                2.04.
                Non-Recourse to any General Partner; No Personal Liability of Officers,
                Directors, Employees, Partners, Etc. 

            	
              2

            
	
               

            	 
	
              ARTICLE
                3
                Miscellaneous 

            	
              3

            
	
              SECTION
                3.01.
                Certain Trustee Matters. 

            	
              3

            
	
              SECTION
                3.02.
                Continued Effect. 

            	
              3

            
	
              SECTION
                3.03.
                Governing Law. 

            	
              3

            
	
              SECTION
                3.04.
                Counterparts. 

            	
              3

            


    

    
 

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

    

 

    FOURTH
      SUPPLEMENTAL INDENTURE, dated as of October 15, 2007 (this
“Fourth Supplemental Indenture”), between
COLORADO INTERSTATE GAS COMPANY, a Delaware corporation
      (the
“Company”), and THE BANK OF NEW YORK TRUST
      COMPANY, N.A., a national banking association (successor-in-interest to
      Harris Trust and Savings Bank), as trustee under the Indenture referred to
      below
      (in such capacity, the “Trustee”).

     

    RECITALS
      OF
      THE COMPANY

     

    WHEREAS,
      the
      Company and the Trustee are parties to an Indenture, dated as of June 27, 1997
      (the “Original Indenture”), as amended and
      supplemented by (i) the First Supplemental Indenture thereto dated as of June
      27, 1997 (the “First Supplemental Indenture”), (ii)
      the Second Supplemental Indenture thereto dated as of March 9, 2005 (the
“Second Supplemental Indenture”) and (iii) the Third
      Supplemental Indenture thereto dated as of November 1, 2005 (the
“Third Supplemental Indenture”) (the Original
      Indenture, as supplemented from time to time, including without limitation
      pursuant to the First Supplemental Indenture, the Second Supplemental Indenture,
      the Third Supplemental Indenture and this Fourth Supplemental Indenture, being
      referred to herein as the “Indenture”);
      and

     

    WHEREAS,
      Section
      9.02 of the Original Indenture provides that, with the consent of the Holders
      of
      not less than a majority in principal amount of the outstanding Securities
      of
      all Series affected thereby (voting as a single class), the Company and the
      trustee under the Indenture may enter into an indenture or indentures
      supplemental to the Original Indenture for the purpose of amending or
      supplementing the Indenture; and

     

    WHEREAS,
      all acts
      and things necessary to make this Fourth Supplemental Indenture a valid and
      binding agreement in accordance with the Original Indenture have been done
      or
      performed;

     

    NOW,
      THEREFORE, in
      consideration of the premises, agreements and obligations set forth herein
      and
      for other good and valuable consideration, the receipt and sufficiency of which
      are hereby acknowledged, the parties hereto hereby agree, for the equal and
      proportionate benefit of all Securityholders, as follows:

     

    ARTICLE
      1

    Relation
      to
      Indenture; Definitions

     

    SECTION
      1.01.  Relation
      to Indenture.  

     

    With
      respect to
      each Series of Securities, this Fourth Supplemental Indenture constitutes an
      integral part of the Indenture.

     

    SECTION
      1.02.  Definitions.  

     

    For
      all purposes of
      this Fourth Supplemental Indenture, capitalized terms used herein and not
      otherwise defined herein shall have the meanings assigned thereto in the
      Original Indenture.

     

    SECTION
      1.03.  General
      References.  

     

    All
      references in
      this Fourth Supplemental Indenture to Articles and Sections, unless otherwise
      specified, refer to the corresponding Articles and Sections of this Fourth
      Supplemental Indenture; and the terms “herein”, “hereof”,
“hereunder” and any other word of similar import refers to
      this Fourth
      Supplemental Indenture.

     

    ARTICLE
      2

    Amendments
      to Original Indenture

     

    With
      respect to
      each Series of Securities, the Original Indenture is hereby amended as set
      forth
      below.

     

    SECTION
      2.01.  Legal
      Existence.  

     

    Section
      4.03 of the
      Original Indenture is hereby amended and restated to read, in its entirety,
      as
      follows:

     

    SECTION
      4.03  Legal Existence.

     

    Subject
      to Article
      5 and Section 4.04, the Company will do or cause to be done all things necessary
      to preserve and keep in full force and effect its legal existence and the rights
      (charter and statutory) and material franchises of the Company;
provided, however, that the Company shall not be required to
      preserve any such right or franchise if the Board of Directors or management
      of
      the Company shall determine that the preservation thereof is no longer desirable
      in the conduct of the business of the Company and its Subsidiaries, taken as
      a
      whole, and if the loss thereof is not, and will not be, adverse in any material
      respect to the Holders; and provided further that this Section 4.03
      shall not prohibit the Company from consummating any statutory conversion of
      the
      Company into any form of non-corporate legal entity (including without
      limitation a general partnership, limited partnership or limited liability
      company) so long as (immediately after giving effect to such conversion) at
      least one corporation is a co-issuer party to this Indenture and to each Series
      of Securities at any time issued hereunder and is jointly and severally liable
      with respect to any and all obligations of the Company under this Indenture
      and
      each such Series of Securities, as a primary obligor and not as a guarantor
      or
      surety.

     

    SECTION
      2.02.  When
      Company May Merge, Etc.  

     

    The
      last paragraph
      of Section 5.01 of the Original Indenture is hereby amended and restated to
      read, in its entirety, as follows:

     

    Notwithstanding
      the
      foregoing, (i) any Subsidiary may consolidate with, merge with or into or
      transfer all or part of its properties and assets to the Company or any other
      Subsidiary or Subsidiaries and (ii) this Section 5.01 shall not prohibit the
      Company from consummating any statutory conversion of the Company into any
      form
      of non-corporate legal entity (including without limitation a general
      partnership, limited partnership or limited liability company) so long as
      (immediately after giving effect to such conversion) at least one corporation
      is
      a co-issuer party to this Indenture and to each Series of Securities at any
      time
      issued hereunder and is jointly and severally liable with respect to any and
      all
      obligations of the Company under this Indenture and each such Series of
      Securities, as a primary obligor and not as a guarantor or surety.

     

    SECTION
      2.03.  Amendments,
      Supplements and Waivers Without Consent of Holders.

     

    Section
      9.01 of the
      Original Indenture is hereby amended as follows:

     

    
      	
               

            	
              (a)

            	
              by
                deleting
                the “or” appearing at the end of clause
                (6);

            


    

     

    
      	
               

            	
              (b)

            	
              by
                deleting
                the period (“.”) appearing at the end of clause (7) and replacing it with
                “; and”; and

            


    

     

    
      	
               

            	
              (c)

            	
              by
                adding the
                following additional clause (8) to appear immediately following clause
                (7):

            


    

     

    (8)  to
      add a corporate co-issuer party to this Indenture and each Series of Securities
      as described in Sections 4.03 and 5.01 of this Indenture.

     

    SECTION
      2.04.  Non-Recourse
      to any General Partner; No Personal Liability of Officers, Directors, Employees,
      Partners, Etc.

     

    Section
      10.10 of
      the Original Indenture is hereby amended and restated to read, in its entirety,
      as follows:

     

    SECTION
      10.10  Non-Recourse to any General Partner; No Personal Liability
      of Officers, Directors, Employees, Partners, Etc.

     

    The
      Trustee, and
      each Holder of a Security by its acceptance thereof, will be deemed to have
      agreed in this Indenture that (1) neither any general partner of the Company
      nor
      such general partner's assets (nor any of its Affiliates other than the Company
      or any corporate co-issuer, nor their respective assets) shall be liable for
      any
      of the obligations of the Company or any corporate co-issuer under this
      Indenture or such Securities, and (2) no director, officer, employee,
      stockholder, member, manager, limited partner or other holder of the equity
      securities, as such, of the Company, any corporate co-issuer, the Trustee,
      any
      general partner of the Company or any Affiliate of any of the foregoing entities
      shall have any personal liability in respect of the obligations of the Company
      or any corporate co-issuer under this Indenture or such Securities by reason
      of
      his, her or its status.  Accordingly, without limiting the generality
      of the foregoing, obligations of the Company and any corporate co-issuer under
      this Indenture and the Securities hereunder are non-recourse to any general
      partner, director, officer, employee, stockholder, member, manager, limited
      partner or other holder of the equity securities, as such, of the Company or
      any
      corporate co-issuer and their respective Affiliates (other than the Company
      or
      any corporate co-issuer), and are payable only out of the cash flow and assets
      of the Company and any corporate co-issuer.

     

    ARTICLE
      3

    Miscellaneous

     

    SECTION
      3.01.  Certain
      Trustee Matters. 

     

    The
      recitals
      contained herein shall be taken as the statements of the Company, and the
      Trustee assumes no responsibility for their correctness.

     

    The
      Trustee makes
      no representations as to the validity or sufficiency of this Fourth Supplemental
      Indenture or the proper authorization or the due execution hereof by the
      Company.

     

    SECTION
      3.02.  Continued
      Effect. 

     

    Except
      as expressly
      supplemented and amended by this Fourth Supplemental Indenture, the Original
      Indenture (as supplemented and amended by the First Supplemental Indenture,
      the
      Second Supplemental Indenture and the Third Supplemental Indenture) shall
      continue in full force and effect in accordance with the provisions thereof,
      and
      the Original Indenture (as supplemented and amended by the First Supplemental
      Indenture, the Second Supplemental Indenture, the Third Supplemental Indenture
      and this Fourth Supplemental Indenture) is in all respects hereby ratified
      and
      confirmed.  This Fourth Supplemental Indenture and all its provisions
      shall be deemed a part of the Original Indenture in the manner and to the extent
      herein and therein provided.

     

    SECTION
      3.03.  Governing
      Law.  

     

    This
      Fourth
      Supplemental Indenture shall be governed by and construed in accordance with
      the
      laws of the State of New York.

     

    SECTION
      3.04.  Counterparts. 

     

    This
      instrument may
      be executed in any number of counterparts, each of which shall be deemed to
      be
      an original, but all such counterparts shall together constitute but one and
      the
      same instrument.

     

    


     

     

    (Signature
      Page
      Follows)

     


    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    


    IN
      WITNESS WHEREOF,
      the parties hereto have caused this Fourth Supplemental Indenture to be duly
      executed and delivered, all as of the day and year first above
      written.

     

    


    


    COLORADO
      INTERSTATE
      GAS COMPANY

    


    


    By:       /s/John
      J.
      Hopper                                         

    Name:  John
      J. Hopper

    Title:    Vice
      President and Treasurer

    


    


    


    


    THE
      BANK OF NEW
      YORK TRUST COMPANY, N.A.

    as
      Trustee

    


    


    By:        /s/Brian
      Echausee                                        

    Brian
      Echausee, Trust Officer

                 
      Authorized Signatory