UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                               (Amendment No.)*

                                NRG ENERGY, INC.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                     Common Stock, $0.01 Par Value Per Share
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    629377508
                                    ---------
                                 (CUSIP Number)


                                February 17, 2006
                                -----------------
                      (Date of Event which Requires Filing
                               of this Statement)



Check the appropriate box to designate the rule pursuant to which this Schedule
                                    is filed:

                                [ ] Rule 13d-1(b)
                                [X] Rule 13d-1(c)
                                [ ] Rule 13d-1(d)



*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).


                                  Page 1 of 10




-------------------                                           ------------------
CUSIP No. 629377508                    13G                    Page 2 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Advisors, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) [ ]

                                                                         (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       2,495,630* (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            2,495,630* (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           2,495,630* (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           3.1% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 2 of 10




-------------------                                           ------------------
CUSIP No. 629377508                    13G                    Page 3 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Management, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) [ ]

                                                                         (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       2,495,630* (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            2,495,630* (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           2,495,630* (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           3.1% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 3 of 10




-------------------                                           ------------------
CUSIP No. 629377508                    13G                    Page 4 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           CR Intrinsic Investors, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) [ ]

                                                                         (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
-------------------- ------ ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF            ------ ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       1,585,000+ (see Item 4)
BY                   ------ ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                 ------ ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            1,585,000+ (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           1,585,000+ (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           2.0% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 4 of 10




-------------------                                           ------------------
CUSIP No. 629377508                    13G                    Page 5 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Steven A. Cohen
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) [ ]

                                                                         (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY
---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           United States
-------------------- ------ ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF            ------ ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       4,080,630*+ (see Item 4)
BY                   ------ ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                 ------ ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            4,080,630*+ (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           4,080,630*+ (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           5.0% (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           IN
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 5 of 10




Item 1(a)           Name of Issuer:
                    --------------

                    NRG Energy, Inc.

Item 1(b)           Address of Issuer's Principal Executive Offices:
                    -----------------------------------------------

                    211 Carnegie Center
                    Princeton, New Jersey 08540

Items 2(a)          Name of Person Filing:
                    ---------------------

                    This statement is filed by: (i) S.A.C. Capital Advisors,
                    LLC, ("SAC Capital Advisors") with respect to shares of
                    common stock, $.01 par value per share ("Shares")
                    beneficially owned by S.A.C. Capital Associates, LLC ("SAC
                    Capital Associates"), S.A.C. Arbitrage Fund, LLC ("SAC
                    Arbitrage"), S.A.C. MultiQuant Fund, LLC ("SAC MultiQuant")
                    and S.A.C. Select Fund, LLC ("SAC Select"); (ii) S.A.C.
                    Capital Management, LLC, ("SAC Capital Management") with
                    respect to Shares beneficially owned by SAC Capital
                    Associates, SAC Arbitrage, SAC MultiQuant and SAC Select;
                    (iii) CR Intrinsic Investors, LLC ("CR Intrinsic Investors")
                    with respect to Shares beneficially owned by CR Intrinsic
                    Investments, LLC ("CR Intrinsic Investments"); and (iv)
                    Steven A. Cohen with respect to Shares beneficially owned by
                    SAC Capital Advisors, SAC Capital Management, SAC Capital
                    Associates, SAC Arbitrage, SAC MultiQuant, SAC Select, CR
                    Intrinsic Investors and CR Intrinsic Investments.

Item 2(b)           Address of Principal Business Office:
                    ------------------------------------

                    The address of the principal business office of (i) SAC
                    Capital Advisors, CR Intrinsic Investors and Mr. Cohen is 72
                    Cummings Point Road, Stamford, Connecticut 06902 and (ii)
                    SAC Capital Management is 540 Madison Avenue, New York, New
                    York 10022.

Item 2(c)           Citizenship:
                    -----------

                    SAC Capital Advisors, SAC Capital Management and CR
                    Intrinsic Investors are Delaware limited liability
                    companies. Mr. Cohen is a United States citizen.

Item 2(d)           Title of Class of Securities:
                    ----------------------------

                    Common Stock, par value $0.01 per share


                                  Page 6 of 10




Item 2(e)           CUSIP Number:
                    ------------

                    629377508

Item 3              Not Applicable

Item 4              Ownership:
                    ---------

                    The percentages used herein are calculated based upon the
                    Shares issued and outstanding as of November 3, 2005 as
                    reported on the Issuer's quarterly report on Form 10-Q filed
                    with the Securities and Exchange Commission by the Issuer
                    for the quarterly period ended September 30, 2005, plus
                    Shares issuable upon conversion of the Issuer's 4%
                    Convertible Perpetual Preferred Stock held by SAC Arbitrage
                    as described below.

                    As of the close of business on February 17, 2006:

                    1. S.A.C. Capital Advisors, LLC
                    (a) Amount beneficially owned: 2,495,630*
                    (b) Percent of class: 3.1%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 2,495,630*
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    2,495,630*

                    2. S.A.C. Capital Management, LLC
                    (a) Amount beneficially owned: 2,495,630*
                    (b) Percent of class: 3.1%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 2,495,630*
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    2,495,630*

                    3. CR Intrinsic Investors, LLC
                    (a) Amount beneficially owned: 1,585,000+
                    (b) Percent of class: 2.0%
                    (c) (i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 1,585,000+
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    1,585,000+

                    4. Steven A. Cohen
                    (a) Amount beneficially owned: 4,080,630* +
                    (b) Percent of class: 5.0%
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 4,080,630* +
                    (iii) Sole power to dispose or direct the disposition: -0-


                               Page 7 of 10 Pages




                    (iv) Shared power to dispose or direct the disposition:
                    4,080,630* +

                    * The number of shares reported herein includes (i) 200,000
                    shares issuable upon conversion of 8000 shares of the
                    Issuer's 4% Convertible Perpetual Preferred Stock held by
                    SAC Arbitrage and (ii) 750,000 shares issuable upon exercise
                    of options held by SAC Capital Associates.

                    + The number of shares reported herein includes 1,400,000
                    shares issuable upon exercise of options held by CR
                    Intrinsic Investments.

                    SAC Capital Advisors, SAC Capital Management, CR Intrinsic
                    Investors and Mr. Cohen own directly no Shares. Pursuant to
                    investment agreements, each of SAC Capital Advisors and SAC
                    Capital Management share all investment and voting power
                    with respect to the securities held by SAC Capital
                    Associates, SAC Arbitrage and SAC MultiQuant. Pursuant to an
                    investment management agreement, CR Intrinsic Investors has
                    investment and voting power with respect to the securities
                    held by CR Intrinsic Investments. Mr. Cohen controls each of
                    SAC Capital Advisors and SAC Capital Management. CR
                    Intrinsic Investments is a wholly owned subsidiary of SAC
                    Capital Associates. By reason of the provisions of Rule
                    13d-3 of the Securities Exchange Act of 1934, as amended,
                    each of (i) SAC Capital Advisors, SAC Capital Management and
                    Mr. Cohen may be deemed to own beneficially 2,495,630 Shares
                    (constituting approximately 3.1% of the Shares outstanding)
                    and (ii) CR Intrinsic Investors and Mr. Cohen may be deemed
                    to own beneficially 1,585,000 Shares (constituting
                    approximately 2.0% of the Shares outstanding). Each of SAC
                    Capital Advisors, SAC Capital Management, CR Intrinsic
                    Investors and Mr. Cohen disclaim beneficial ownership of any
                    of the securities covered by this statement, and SAC Capital
                    Associates disclaims beneficial ownership of any of the
                    securities held by CR Intrinsic Investments.

Item 5              Ownership of Five Percent or Less of a Class:
                    --------------------------------------------

                    If this statement is being filed to report the fact that as
                    of the date hereof the reporting person has ceased to be the
                    beneficial owner of more than five percent of the class of
                    securities, check the following. [ ]

Item 6              Ownership of More than Five Percent on Behalf of Another
                    --------------------------------------------------------
                    Person:
                    ------

                    Not Applicable


                               Page 8 of 10 Pages




Item 7              Identification and Classification of the Subsidiary Which
                    ---------------------------------------------------------
                    Acquired the Security Being Reported on By the Parent
                    -----------------------------------------------------
                    Holding Company:
                    ---------------

                    Not Applicable

Item 8              Identification and Classification of Members
                    --------------------------------------------
                    of the Group:
                    ------------

                    Not Applicable

Item 9              Notice of Dissolution of Group:
                    ------------------------------

                    Not Applicable

Item 10             Certification:
                    -------------

     By signing below the signatory certifies that, to the best of his knowledge
and belief, the securities referred to above were not acquired and are not held
for the purpose of or with the effect of changing or influencing the control of
the issuer of the securities and were not acquired and are not held in
connection with or as a participant in any transaction having that purpose or
effect.


                               Page 9 of 10 Pages




                                    SIGNATURE
                                    ---------

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


Dated: February 27, 2006


S.A.C. CAPITAL ADVISORS, LLC

By: /s/ Peter Nussbaum
    ------------------------------
Name:  Peter Nussbaum
Title: Authorized Person


S.A.C. CAPITAL MANAGEMENT, LLC

By: /s/ Peter Nussbaum
    ------------------------------
Name:  Peter Nussbaum
Title: Authorized Person


CR INTRINSIC INVESTORS, LLC

By: /s/ Peter Nussbaum
    ------------------------------
Name:  Peter Nussbaum
Title: Authorized Person


STEVEN A. COHEN

By: /s/ Peter Nussbaum
    ------------------------------
Name:  Peter Nussbaum
Title: Authorized Person