Exhibit 10.7


    
      

    

    Exhibit
      10.7



    FIRST
      AMENDMENT TO THE

     

    FIRST
      AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP OF

     

    RIO
      VISTA OPERATING PARTNERSHIP L.P.

     

    This
      First Amendment to the First Amended and Restated Agreement of Limited
      Partnership of Rio Vista Operating Partnership L.P., dated as of October 26,
      2005 (this “First Amendment”), is entered into by and between Rio Vista
      Operating GP LLC, a Delaware limited liability company, as the General Partner,
      and Rio Vista Energy Partners L.P., a Delaware limited partnership, as the
      sole
      Limited Partner, of Rio Vista Operating Partnership L.P., a Delaware limited
      partnership (the “Operating Partnership”). Capitalized terms used, and not
      otherwise defined, herein shall have the same meaning as set forth in the First
      Amended and Restated Agreement of Limited Partnership of the Operating
      Partnership dated as of September 16, 2004 (the “Operating Partnership
      Agreement”).

     

    WHEREAS,
      the General Partner and the Limited Partner are party to the Operating
      Partnership Agreement; and

     

    WHEREAS,
      in accordance with Section 13.2 of the Operating Partnership Agreement, the
      General Partner and the Limited Partner wish to amend the Operating Partnership
      Agreement on the terms set forth herein.

     

    NOW,
      THEREFORE, the General Partner and the Limited Partner agree as
      follows:

     

    1.            
      Amendment
      of Section 12.1 of the Operating Partnership Agreement.
      Paragraph (d)
      of Section 12.1 (Dissolution) of the Operating Partnership Agreement which
      currently reads:

     

    
      	 	
              “(d)

            	
              the
                sale of all or substantially all of the assets and properties of
                the
                Partnership Group.”

            


    

    


    is
      hereby
      amended to read as follows: 

    


    
      	 	
              “(d)

            	
              the
                distribution to the Partners of all or substantially all of the net
                proceeds from the sale of all or substantially all of the assets
                and
                properties of the Partnership.”

            


    

    


    2.            
      Effect
      of This Amendment.
      Except
      as expressly provided in this First Amendment, the Operating Partnership
      Agreement is reaffirmed and remains in full force and effect. 

    


    3.            
      Incorporation
      by Reference.
      The
      provisions of the Operating Partnership Agreement, including without limitation
      Article 15 (General
      Provisions),
      are
      incorporated herein by reference. All references to “this Agreement” contained
      in such provisions shall be deemed to refer to the Operating Partnership
      Agreement, as amended by this First Amendment.


    
      
        
        

      

      
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    IN
      WITNESS WHEREOF, the parties have executed this First Amendment to the First
      Amended and Restated Agreement of Limited Partnership of Rio Vista Operating
      Partnership L.P. as of the day and year first set forth above.

    


    
      	 	
              GENERAL
                PARTNER:

            	 
	 	 	 	 
	 	
              RIO
                VISTA OPERATING GP LLC,

            	 
	 	
              a
                Delaware limited liability company

            	 
	 	 	 	 
	 	 	 	 
	 	
              By:
                

            	/s/
              Charles C. Handly	 
	 	 	
              Charles
                C. Handly, President

            	 
	 	 	 	 
	 	 	 	 
	 	 	 	 
	 	
              LIMITED
                PARTNER:

            	 
	 	 	 	 
	 	
              RIO
                VISTA ENERGY PARTNERS L.P., 

            	 
	 	
              a
                Delaware limited partnership

            	 
	 	 	 	 
	 	
              By:

            	
              Rio
                Vista GP LLC, its General Partner

            	 
	 	 	 	 
	 	 	 	 
	 	
              By:

            	/s/
              Charles C. Handly	 
	 	 	Charles
              C. Handly, President	 


    

     

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