Amendment of Stock Purchase Agreement (Luz Sale)




 Exhibit 10.51 
  
 EXELON SHC, INC. 
 EXELON NEW ENGLAND POWER MARKETING, L.P. 
 c/o Exelon Generation Company, LLC 
 300 Exelon Way 
 Kennett Square, PA 19348 
  
 January 31, 2005 
  
 Dynegy New York Holdings Inc. 
 c/o Dynegy Inc.

 1000 Louisiana Street, Suite 5800 
 Houston, TX 77002

 Attention: Alec G. Dryer 
  
 ExRes SHC, Inc. 
 355 Madison Avenue 
 18th Floor 
 New York, NY 10017 
 Attention: Todd Cutler 
  
 Re: Amendment of Stock Purchase Agreement—Luz Sale 
  
 Gentlemen: 
  
 Reference is made
to that certain Stock Purchase Agreement, dated as of November 1, 2004, as amended by those certain letter agreements dated December 2, 2004, December 31, 2004 and January 31, 2005 (the “SPA”), in each case by and among Exelon SHC, Inc.,
Exelon New England Power Marketing, L.P., Dynegy new York Holdings Inc. and ExRes SHC, Inc. Capitalized terms used herein without definition shall have the definitions given such terms in the SPA. 
  
 Section 2.4 of the SPA provides for certain Purchase Price adjustments. The
Parties to the SPA desire to amend the SPA to provide for another Purchase Price adjustment related to the possible sale of the Sithe’s indirect interest in Luz Solar Partners Ltd., III. Section 2.4 of the SPA is hereby amended to add the
following as new clause (h) of Section 2.4 immediately after clause (g) of Section 2.4: 
  
 “(h) In addition, in the event that Sithe or its Subsidiaries have not received the purchase price payable with respect to the sale
of Sithe’s indirect interest in Luz Solar Partners Ltd., III by 11:59 p.m. on February 1, 2005, the Purchase Price shall be decreased by $1,151,510.26. Notwithstanding the provisions of Section 6.1(e), if Sithe or its Subsidiaries have not
received the purchase price payable with respect to the sale of Sithe’s indirect interest in Luz Solar Partners Ltd., III by 11:59 p.m. on 









 
January 31, 2005, the Parties hereby agree and acknowledge that the aggregate amount of unrestricted cash in ExRes and Sithe as of the Closing Date as
required by Section 6.1(e) shall be reduced by $1,151,510.26.” 
  
 Execept as amended, modified or waived hereby, the SPA remains in full force and effect and is hereby ratified and affirmed. This letter agreement may be executed in any number of counterparts, all of which taken together shall constitute
one and the same amendatory instrument, and any of the parties hereto may execute this letter agreement by signing any such counterpart. This letter agreement shall be governed by, and construed in accordance with, the internal laws of the State of
New York. 
  
 [Signature Page Follows] 
  

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 IN WITNESS WHEREOF, the parties have duly executed this letter agreement as of the date first above
written. 
  

			
	EXELON SHC, INC.
		
	By:	 	/s/ Todd D. Cutler
	Name:	 	Todd D. Cutler
	Title:	 	Assistant Secretary
	
	EXELON NEW ENGLAND POWER MARKETING, L.P.
		
	By:	 	/s/ Todd D. Cutler
	Name:	 	Todd D. Cutler
	Title:	 	 Assistant Secretary of Exelon AOG Holding #1, Inc.,
its General Partner

	
	DYNEGY NEW YORK HOLDINGS INC.
		
	By:	 	/s/ Alec Dryer
	Name:	 	Alec Dryer
	Title:	 	President
	
	EXRES SHC, INC.
		
	By:	 	/s/ Todd D. Cutler
	Name:	 	Todd D. Cutler
	Title:	 	Assistant Secretary

  

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