exhibit4a.htm


    EXHBIIT
      4.A

     

    
 

    SOUTHERN
      NATURAL GAS COMPANY

     

    


    as
      Issuer

     

    


     

     SOUTHERN
      NATURAL ISSUING CORPORATION

     

    


    as
      Co-issuer

     

    


     

    WILMINGTON
      TRUST COMPANY

     

    


    as
      Original
      Trustee

     

    


     

    and

     

    


     

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

     

    


    as
      Series
      Trustee

     

    


     

    SIXTH
      SUPPLEMENTAL INDENTURE

     

    


    Dated
      as of
      November 1, 2007

     

    


     

    To

     

    


     

    INDENTURE

     

    


    Dated
      as of
      June 1, 1987

     

    
      

        
          
            
            

          

          
            
            

            
              

            

          

          
            
            

          

        



    

     

     

    TABLE
      OF CONTENTS

    
 

    
      	 	
              Page

            
	
              ARTICLE
                1 Relation to Indenture;
                Definitions.

            	
              2

            
	
              SECTION
                1.01.
                Relation to Indenture. 

            	
              2

            
	
              SECTION
                1.02.
                Definitions. 

            	
              2

            
	
              SECTION
                1.03.
                General References. 

            	
              2

            
	
               

            	 
	
              ARTICLE
                2
                Amendments to Original Indenture. 

            	
              2

            
	
              SECTION
                2.01.
                Co-issuer Party.

            	
              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

            


    

    


    
      
        
          
          

        

        
          
          

          
            

          

        

        
          
          

        

      

    

    


    
 

    
 

    SIXTH
      SUPPLEMENTAL INDENTURE, dated as of November 1, 2007 (this
      "Sixth Supplemental Indenture"), among (i)
SOUTHERN NATURAL GAS COMPANY, a Delaware corporation (the
      "Company"), (ii) SOUTHERN NATURAL ISSUING
      CORPORATION, a Delaware corporation ("Finance
      Corp"), (iii) WILMINGTON TRUST COMPANY, a
      Delaware banking corporation, as trustee under the Indenture referred to below
      except as otherwise provided below (in such capacity, the "Original
      Trustee") (as successor-in-interest to JPMorgan Chase Bank,
      National Association, successor to Manufacturers Hanover Trust Company, pursuant
      to the Instrument of Resignation, Appointment and Acceptance, dated as of
      February 27, 2003 (the "2003 Resignation and
      Appointment")), and (iv) THE BANK OF NEW YORK TRUST
      COMPANY, N.A., a national banking association, as trustee under the
      Indenture referred to below with respect to the series of Securities designated
      5.90% Notes Due 2017 issued pursuant to the Third Supplemental Indenture (as
      defined below) (in such capacity, the "Series
      Trustee").

     

    RECITALS
      OF
      THE COMPANY

     

    WHEREAS,
      the
      Company has issued Securities pursuant to the Indenture, dated as of June 1,
      1987 (the "Original Indenture"), as amended and
      supplemented by (i) the First Supplemental Indenture, dated as of September
      30,
      1997 (the "First Supplemental Indenture"), (ii) the
      Second Supplemental Indenture, dated as of February 13, 2001 (the
      "Second Supplemental Indenture"), (iii) the 2003
      Resignation and Appointment, (iv) the Third Supplemental Indenture, dated as
      of
      March 26, 2007 (the "Third Supplemental Indenture"),
      (v) the Fourth Supplemental Indenture, dated as of May 4, 2007 (the
      "Fourth Supplemental Indenture"), and (vi) the Fifth
      Supplemental Indenture, dated as of October 15, 2007 (the "Fifth
      Supplemental Indenture") (the Original Indenture, as so amended
      and supplemented by the First Supplemental Indenture, the Second Supplemental
      Indenture, the 2003 Resignation and Appointment, the Third Supplemental
      Indenture, the Fourth Supplemental Indenture and the Fifth Supplemental
      Indenture, being referred to herein as the
      "Indenture"); and

     

    WHEREAS,
      the
      Company intends to convert to a Delaware general partnership by the filing
      of a
      Certificate of Conversion with the Secretary of State of the State of Delaware
      (the "Conversion"); and

     

    WHEREAS,
      the
      Conversion is permitted by the terms of the Indenture so long as, immediately
      after giving effect to the Conversion, at least one corporation is a co-issuer
      party to the Indenture and to each series of Securities at any time issued
      thereunder and is jointly and severally liable with respect to any and all
      obligations of the Company under the Indenture and each such series of
      Securities, as a primary obligor and not as a guarantor or surety;
      and

     

    WHEREAS,
      Section
      12.01 of the Indenture provides that the Company, the Original Trustee and
      the
      Series Trustee may from time to time and at any time, without the consent of
      the
      Holders of the Outstanding Securities, enter into an indenture or indentures
      supplemental to the Indenture for the purpose of adding a corporate co-issuer
      party to the Indenture and to each series of Securities; and

     

    WHEREAS,
      the
      parties hereto desire to amend the Indenture to add Finance Corp as a co-issuer
      party to  the Indenture and to each series of Securities;
      and

     

    WHEREAS,
      the
      Company has heretofore delivered or is delivering contemporaneously herewith
      to
      the Original Trustee and the Series Trustee (i) a copy of resolutions of the
      Board of Directors of the Company and a copy of resolutions of the Board of
      Directors of Finance Corp, each authorizing the execution of this Sixth
      Supplemental Indenture, (ii) the Opinion of Counsel referred to in Section
      12.06
      of the Indenture and (iii) an Officers' Certificate in connection herewith;
      and

     

    WHEREAS,
      all acts
      and things necessary to make this Sixth Supplemental Indenture a valid and
      binding agreement in accordance with the 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 Sixth Supplemental Indenture constitutes an
      integral part of the Indenture.

     

    SECTION
      1.02.  Definitions.  

     

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

     

    SECTION
      1.03.  General
      References.  

     

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

     

    ARTICLE
      2

    Amendments
      to Original Indenture

     

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

     

    SECTION
      2.01.  Co-issuer
      Party.  

     

    Article
      Sixteen of
      the Original Indenture is hereby amended by adding the following Section 16.13
      thereto:

     

    SECTION
      16.13                                
Finance Corp is hereby designated as a co-issuer party under this Indenture
      and
      to each series of Securities at any time issued under this
      Indenture.  Finance Corp hereby assumes, agrees
      to be bound by, and agrees to be jointly and severally liable, as a primary
      obligor and not as a guarantor or surety, with respect to, any and all
      obligations of the Company under this Indenture and each such series of
      Securities.  The provisions of this Section 16.13 shall become
      effective at the time that the Company  converts to a Delaware general
      partnership by the filing of a Certificate of Conversion with the Secretary
      of
      State of the State of Delaware.

     

    ARTICLE
      3

    Miscellaneous

     

    SECTION
      3.01.  Certain
      Trustee Matters. 

     

    The
      recitals
      contained herein shall be taken as the statements of the Company and Finance
      Corp, and neither the Original Trustee nor the Series Trustee assumes any
      responsibility for their correctness.

     

    Neither
      the
      Original Trustee nor the Series Trustee makes any representations as to the
      validity or sufficiency of this Sixth Supplemental Indenture or the proper
      authorization or the due execution hereof by the Company or Finance
      Corp.

     

    In
      entering into
      this Sixth Supplemental Indenture, the Original Trustee and the Series Trustee
      shall be entitled to the benefit of every provision of the Indenture (to the
      extent applicable to the Original Trustee or Series Trustee, as the case may
      be), whether or not elsewhere herein so provided.

     

    SECTION
      3.02.  Continued
      Effect. 

     

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

     

    SECTION
      3.03.  Governing
      Law.  

     

    This
      Sixth
      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 Sixth Supplemental Indenture to be duly
      executed and delivered, all as of the day and year first above
      written.

    
       

      
        	
                SOUTHERN
                  NATURAL GAS COMPANY

              
	 
	 
	
                By:

              	
                /s/
                  John J.
                  Hopper

              
	
                John
                  J. Hopper

              
	
                Vice
                  President and
                  Treasurer

              


      

       

      


      
        	
                SOUTHERN
                  NATURAL ISSUING CORPORATION

              
	 
	 
	
                By:

              	
                /s/
                  John J.
                  Hopper

              
	
                John
                  J. Hopper

              
	
                Vice
                  President and
                  Treasurer

              


      

      


       

      
        	
                WILMINGTON
                  TRUST COMPANY

                as
                  Original
                  Trustee

              
	 
	 
	
                By:

              	
                /s/
                  Michael
                  G. Oller, Jr.

              
	
                Michael
                  G. Oller,
                  Jr.

              
	
                Senior
                  Financial Services
                  Officer

              


      

       

      


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

                as
                  Series
                  Trustee

              
	 
	 
	
                By:

              	
                /s/
                  Brian
                  Echausse

              
	
                Brian
                  Echausse

              
	
                Trust
                  Officer