Exhibit
4.12


SECOND
SUPPLEMENTAL INDENTURE 

ADDITIONAL SUBSIDIARY GUARANTEES


SECOND SUPPLEMENTAL INDENTURE
(this “Supplemental Indenture”),
dated as of September 21, 2006, among Reliant Energy Power Supply,
LLC (the “Guaranteeing Subsidiary”),
a subsidiary of Reliant Energy, Inc. (or its permitted successor), a Delaware
corporation (the “Company”), the
Company, the other Guarantors (as defined in the Indenture referred to herein)
and Wilmington Trust Company, as trustee under the indenture referred to below
(the “Trustee”).


WITNESSETH


WHEREAS, the Company has heretofore executed and
delivered to the Trustee an indenture (the “Indenture”),
dated as of July 1, 2003 providing for the original issuance of an aggregate
principal amount of $550,000,000 of 9.50% Senior Secured Notes due 2013 (the “Initial Notes”), and, subject to the terms
of the Indenture, future unlimited issuances of 9.50% Senior Secured Notes due
2013 (the “Additional Notes,” and
together with the Initial Notes, the “Notes”);


WHEREAS, the Indenture provides that under certain
circumstances the Guaranteeing Subsidiary shall execute and deliver to the
Trustee a supplemental indenture pursuant to which the Guaranteeing Subsidiary
shall unconditionally guarantee all of the Company’s Obligations under the
Notes and the Indenture (the “Note Guarantee”);
and


WHEREAS, pursuant to Section 9.01 of the Indenture,
the Trustee, the Company and the other Guarantors are authorized to execute and
deliver this Supplemental Indenture.


NOW THEREFORE, in consideration of the foregoing and
for good and valuable consideration, the receipt of which is hereby
acknowledged, the Guaranteeing Subsidiary, the Trustee, the Company and the
other Guarantors mutually covenant and agree for the equal and ratable benefit
of the Holders of the Notes as follows:


1.             Capitalized Terms.  Unless otherwise defined in this Supplemental
Indenture, capitalized terms used herein without definition shall have the
meanings assigned to them in the Indenture.


2.             Agreement to be Bound;
Guarantee.  The Guaranteeing
Subsidiary hereby becomes a party to the Indenture as a Guarantor and as such
will have all of the rights and be subject to all of the Obligations and
agreements of a Guarantor under the Indenture. 
The Guaranteeing Subsidiary hereby agrees to be bound by all of the
provisions of the Indenture applicable to a Guarantor and to perform all of the
Obligations and agreements of a Guarantor under the Indenture.  In furtherance of the foregoing, the Guaranteeing
Subsidiary shall be deemed a Guarantor for purposes of Article 12 of the
Indenture, including, without limitation, Section 12.02 thereof.


3.             NEW YORK LAW TO GOVERN. 
THE INTERNAL LAW OF THE STATE OF NEW YORK SHALL GOVERN AND BE USED TO
CONSTRUE THIS SUPPLEMENTAL INDENTURE BUT WITHOUT GIVING EFFECT TO APPLICABLE 


 



 1
 









 


PRINCIPLES
OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER
JURISDICTION WOULD BE REQUIRED THEREBY.


4.             Counterparts.  The parties may sign any number of copies of
this Supplemental Indenture.  Each signed
copy shall be an original, but all of them together represent the same
agreement.


5.             Effect of Headings.  The Section headings herein are for
convenience only and shall not affect the construction hereof.


6.             The Trustee.  The Trustee shall not be responsible in any
manner whatsoever for or in respect of the validity or sufficiency of this
Supplemental Indenture or for or in respect of the recitals contained herein,
all of which recitals are made solely by the Guaranteeing Subsidiary and the
Company.


7.             Ratification of Indenture;
Supplemental Indenture  Part of Indenture.  Except as expressly amended hereby, the
Indenture is in all respects ratified and confirmed and all the terms,
conditions and provisions thereof shall remain in full force and effect.  This Supplemental Indenture shall form a part
of the Indenture for all purposes, and every Holder of Notes heretofore or
hereafter authenticated and delivered shall by bound hereby.


 



 2
 









 


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


Dated : September 21, 2006.


	
   

  	
  RELIANT ENERGY POWER SUPPLY, LLC

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Lloyd A. Whittington

  
	
   

  	
  Name:

  	
  Lloyd A. Whittington

  
	
   

  	
  Title:

  	
  Vice President and Treasurer

  
	
   

  	
   

  	
   

  
	
   

  	
  RELIANT ENERGY, INC.

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Andrew C. Johannesen

  
	
   

  	
  Name: 

  	
  Andrew C. Johannesen

  
	
   

  	
  Title:

  	
  Vice President and Asst. Treasurer

  



 



 3
 









 


	
  

  	
  RELIANT ENERGY ASSET
  MANAGEMENT, LLC

  
	
   

  	
  RELIANT ENERGY BROADBAND,
  INC.

  
	
   

  	
  RELIANT ENERGY CALIFORNIA
  HOLDINGS, LLC

  
	
   

  	
  RELIANT ENERGY
  COMMUNICATIONS, INC.

  
	
   

  	
  RELIANT ENERGY COOLWATER,
  INC.

  
	
   

  	
  RELIANT ENERGY CORPORATE
  SERVICES, LLC

  
	
   

  	
  RELIANT ENERGY ELLWOOD,
  INC.

  
	
   

  	
  RELIANT ENERGY ETIWANDA,
  INC.

  
	
   

  	
  RELIANT ENERGY FLORIDA,
  LLC

  
	
   

  	
  RELIANT ENERGY KEY/CON
  FUELS, LLC

  
	
   

  	
  RELIANT ENERGY MANDALAY,
  INC.

  
	
   

  	
  RELIANT ENERGY NORTHEAST
  GENERATION, INC.

  
	
   

  	
  RELIANT ENERGY NORTHEAST
  HOLDINGS, INC.

  
	
   

  	
  RELIANT ENERGY ORMOND
  BEACH, INC.

  
	
   

  	
  RELIANT ENERGY POWER
  GENERATION, INC.

  
	
   

  	
  RELIANT ENERGY RETAIL
  HOLDINGS, LLC

  
	
   

  	
  RELIANT ENERGY SABINE
  (TEXAS), INC.

  
	
   

  	
  RELIANT ENERGY SERVICES
  DESERT BASIN, LLC

  
	
   

  	
  RELIANT ENERGY SERVICES
  MID-STREAM, LLC

  
	
   

  	
  RELIANT ENERGY SEWARD, LLC

  
	
   

  	
  RELIANT ENERGY TRADING
  EXCHANGE, INC.

  
	
   

  	
  RELIANT ENERGY VENTURES,
  INC.

  
	
   

  	
  RELIANT ENERGY WHOLESALE GENERATION,
  LLC

  
	
   

  	
   

  	
   

  
	
  

  	
  By:

  	
  /s/ Andrew C. Johannesen

  
	
   

  	
  Name:

  	
  Andrew C. Johannesen

  
	
   

  	
  Title: 

  	
  Assistant Treasurer of the corporations and limited
  liability companies, and of the general partners of the limited partnerships,
  listed above 

  



 



 4
 









 


	
   

  	
  RELIANT ENERGY
  SERVICES, INC.

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Andrew C. Johannesen

  
	
   

  	
  Name: 

  	
  Andrew C. Johannesen

  
	
   

  	
  Title:

  	
  Vice President and Treasurer

  
	
   

  	
   

  	
   

  
	
   

  	
  RELIANT ENERGY RETAIL
  SERVICES, LLC

  
	
   

  	
  RELIANT ENERGY ELECTRIC
  SOLUTIONS, LLC

  
	
   

  	
  RELIANT ENERGY SOLUTIONS
  EAST, LLC

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Lloyd A. Whittington

  
	
   

  	
  Name:

  	
  Lloyd A. Whittington

  
	
   

  	
  Title: 

  	
  Vice President and Treasurer of the limited
  liability companies listed above 

  



 



 5
 









 


	
  

  	
  RELIANT ENERGY CAPTRADES
  HOLDING CORP.

  
	
   

  	
  RELIANT ENERGY SABINE
  (DELAWARE), INC.

  
	
   

  	
   

  	
   

  
	
  

  	
  By:

  	
  /s/ Patricia F. Genzel

  
	
   

  	
  Name:

  	
  Patricia F. Genzel

  
	
   

  	
  Title: 

  	
  President 

  



 



 6
 









 


	
  

  	
  WILMINGTON TRUST COMPANY,
  as Trustee

  
	
   

  	
   

  	
   

  
	
  

  	
  By:

  	
  /s/ Michael G. Oller

  
	
   

  	
  Authorized Signatory

  



 



 7