FORTY-SIXTH SUPPLEMENTAL INDENTURE FOR ADDITIONAL SUBSIDIARY GUARANTEES

EXHIBIT 4.2

FORTY-SIXTH SUPPLEMENTAL INDENTURE FOR
ADDITIONAL SUBSIDIARY GUARANTEES

FORTY-SIXTH SUPPLEMENTAL INDENTURE (this “Supplemental Indenture for Additional Guarantees”), dated as of May 20, 2011, among Energy Protection Insurance Company, Meriden Gas Turbines LLC, NRG Development Company Inc., NRG Energy Labor Services LLC, NRG Energy Services Group LLC, NRG Ilion Limited Partnership, NRG Ilion LP LLC, NRG Maintenance Services LLC, NRG Mextrans Inc., NRG PacGen Inc., NRG Rockford Acquisition LLC, NRG Services Corporation, NRG SimplySmart Solutions LLC, O’Brien Cogeneration, Inc. II, ONSITE Energy, Inc. and Reliant Energy Northeast LLC (each a “Guaranteeing Subsidiary” and together the “Guaranteeing Subsidiaries”), each an indirect subsidiary of NRG Energy, Inc., a Delaware corporation (the “Company”), the Company, the Existing Guarantors set forth on the signature page hereto (the “Existing Guarantors”) and Law Debenture Trust Company of New York, as trustee under the indentures referred to below (the “Trustee”).

W I T N E S S E T H

WHEREAS, the Company has heretofore executed and delivered to the Trustee an indenture (the “Base Indenture”), dated as of February 2, 2006, between the Company and the Trustee, as amended by a ninth supplemental indenture (the “Ninth Supplemental Indenture”), dated as of November 21, 2006, among the Company, the Guarantors named therein and the Trustee, providing for the original issuance of an aggregate principal amount of $1,100 million of 7.375% Senior Notes due 2017 (the “Initial Notes”), and, subject to the terms of the Ninth Supplemental Indenture, future unlimited issuances of 7.375% Senior Notes due 2017 (the “Additional Notes,” and together with the Initial Notes, the “Notes”), as amended by a twelfth supplemental indenture, dated as of July 19, 2007, among the Company, the Existing Guarantors party thereto and the Trustee (the “Twelfth Supplemental Indenture”), a fifteenth supplemental indenture, dated as of August 28, 2007, among the Company, the Existing Guarantors party thereto and the Trustee (the “Fifteenth Supplemental Indenture”), an eighteenth supplemental indenture dated as of April 28, 2009, among the Company, the Existing Guarantors party thereto and the Trustee (the “Eighteenth Supplemental Indenture”), a twenty-first supplemental indenture dated as of May 8, 2009, among the Company, the Existing Guarantors party thereto and the Trustee (the “Twenty-First Supplemental Indenture”), a twenty-sixth supplemental indenture dated as of October 5, 2009, among the Company, the Existing Guarantors party thereto and the Trustee (the “Twenty-Sixth Supplemental Indenture”), a thirtieth supplemental indenture, dated as of April 16, 2010, among the Company, the Existing Guarantors party thereto and the Trustee (the “Thirtieth Supplemental Indenture”), a thirty-fourth supplemental indenture, dated as of June 23, 2010, among the Company, the Existing Guarantors party thereto and the Trustee (the “Thirty-Fourth Supplemental Indenture”) and a thirty-ninth supplemental indenture, dated as of December 15, 2010, among the Company, the Existing Guarantors and the Trustee (the “Thirty-Ninth Supplemental Indenture” and together with the Base Indenture, the Ninth Supplemental Indenture, the Twelfth Supplemental Indenture, the Fifteenth Supplemental Indenture, the Eighteenth Supplemental Indenture, the Twenty-First Supplemental Indenture, the Twenty-Sixth Supplemental Indenture, the Thirtieth Supplemental Indenture and the Thirty-Fourth Supplemental Indenture, the “Indenture”);

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

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WHEREAS, pursuant to Section 4.17 of the Ninth Supplemental Indenture, the Trustee, the Company and the Existing Guarantors are authorized and required to execute and deliver this Supplemental Indenture for Additional Guarantees.

NOW THEREFORE, in consideration of the foregoing and for good and valuable consideration, the receipt of which is hereby acknowledged, the Guaranteeing Subsidiaries, the Trustee, the Company and the Existing 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 for Additional Guarantees, capitalized terms used herein without definition shall have the meanings assigned to them in the Indenture.

2.             Agreement to Be Bound; Guarantee.  The Guaranteeing Subsidiaries hereby become parties to the Indenture as Guarantors and as such will have all of the rights and be subject to all of the Obligations and agreements of Guarantors under the Indenture.  The Guaranteeing Subsidiaries hereby agree 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 Subsidiaries shall be deemed Guarantors for purposes of Article 10 of the Ninth Supplemental Indenture, including, without limitation, Section 10.02 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 FOR ADDITIONAL GUARANTEES BUT WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.