SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
X	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* BLACKSTONE MANAGEMENT ASSOCIATES IV LLC (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol NRG ENERGY, INC. [ NRG ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks
	3. Date of Earliest Transaction (Month/Day/Year) 08/15/2006
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.01 per share	08/15/2006		S		3,309,582	D	$48.41(1)	3,309,583	I	See footnotes(1)(2)(3)(4)
Common Stock, par value $0.01 per share	08/15/2006		S		629,828	D	$48.41(1)	629,827	I	See footnotes(1)(2)(3)(4)
Common Stock, par value $0.01 per share	08/15/2006		S		57,685	D	$48.41(1)	57,685	I	See footnotes(1)(2)(3)(4)
Common Stock, par value $0.01 per share	08/15/2006		S		208,160	D	$48.41(1)	208,160	I	See footnotes(1)(2)(3)(4)
Common Stock, par value $0.01 per share	08/15/2006		S		7,625	D	$48.41(1)	7,626	I	See footnotes(1)(2)(3)(4)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* BLACKSTONE MANAGEMENT ASSOCIATES IV LLC (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* Blackstone TG Capital Partners IV L.P. (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* Blackstone TG Capital Partners IV-B L.P. (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* BLACKSTONE CAPITAL PARTNERS IV-A LP (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* BLACKSTONE FAMILY INVESTMENT PARTNERSHIP IV-A LP (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* Blackstone Participation Partnership IV L.P. (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* PETERSON PETER G (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* SCHWARZMAN STEPHEN A (Last) (First) (Middle) C/O THE BLACKSTONE GROUP 345 PARK AVENUE (Street) NEW YORK NY 10154 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) See Remarks

Explanation of Responses:

1. On August 15, 2006, Blackstone TG Capital Partners IV L.P. ("BCP IV"), Blackstone TG Capital Partners IV-B L.P. ("BCP IV-B"), Blackstone Capital Partners IV-A L.P. ("BCP IV-A"), Blackstone Family Investment Partnership IV-A L.P. ("BFIP") and Blackstone Participation Partnership IV L.P. ("BPP", and together with BCP IV, BCP IV-B, BCP IV-A and BFIP, the "Blackstone Funds") sold respectively 3,309,582, 629,828, 57,685, 208,160 and 7,625 shares (4,212,880 shares in total) of NRG Energy, Inc.'s common stock (the "Common Stock"), to Morgan Stanley & Co. Incorporated at a price of $48.41 per share (the "Resale"). Following completion of the Resale, BCP IV, BCP IV-B, BCP IV-A, BFIP and BPP directly own respectively 3,309,583, 629,827, 57,685, 208,160 and 7,626 shares of Common Stock reported as beneficially owned in the above table.

2. Blackstone Management Associates IV L.L.C. ("BMA") is the sole general partner of each of the Blackstone Funds and, as such, may be deemed to share beneficial ownership of the shares of Common Stock held by the Blackstone Funds. Messrs. Peter G. Peterson and Stephen A. Schwarzman are the founding members of BMA and, as such, may be deemed to share beneficial ownership of the shares of Common Stock held by the Blackstone Funds.

3. Information with respect to each of the Reporting Persons is given solely by such Reporting Persons, and no Reporting Person has responsibility for the accuracy or completeness of information supplied by another Reporting Person.

4. Pursuant to Rule 16a-1(a)(4) of the Securities Exchange Act of 1934, as amended, each of the Reporting Persons, other than the Blackstone Funds, herein states that this filing shall not be deemed an admission that he or it is the beneficial owner of any of the shares of Common Stock covered by this Statement. Each of BMA, Messrs. Peter G. Peterson and Stephen A. Schwarzman disclaims beneficial ownership of the Common Stock, except to the extent of its or his pecuniary interest in such shares of Common Stock.

Remarks:

As described in Amendment No. 1 to Schedule 13D ("Amendment No. 1") filed on August 11, 2006 with respect to the Common Stock by the Reporting Persons and the other filers listed on the signature pages thereto, as of the date of Amendment No. 1, the Blackstone Funds and certain other Funds (as defined in Amendment No. 1) may have been deemed to be a "group" under Section 13(d) of the Securities Exchange Act and accordingly each Reporting Person may have been deemed to have beneficial ownership of 10% or more of the Common Stock. Following the completion of the Resale, the Reporting Persons are not presently acting in a manner that could deem them to be a "group" with the other Funds within the meaning of Section 13(d) of the Securities Exchange Act with respect to the Common Stock. Each Reporting Person expressly disclaims membership in any such group for the purposes of Section 13(d) of the Securities Exchange Act or for any other purpose. Please see attached Joint Filer Information for signatures of other Reporting Persons.

	/s/ David Foley (on behalf of Blackstone Management Associates IV L.L.C.)	08/16/2006
	** Signature of Reporting Person	Date
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