UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

~~WASHINGTON~~Washington, DC D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 orOR 15(d) of ~~the~~

The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): ~~November~~December 53, 2010

GenOn Energy Holdings, Inc.

(Exact name of registrant as specified in its charter)

Delaware

001-16107

20-3538156

(State or other jurisdiction

of incorporation)

(Commission File Number)

(IRS Employer

Identification No.)



1000 Main Street Houston, Texas		77002
(Address of principal executive offices)		(Zip Code)

Registrant’s telephone number, including area code: (832) 357-3000

Mirant Corporation

~~(Exact~~1155 ~~Name~~Perimeter ofCenter ~~Registrant~~West, asSuite ~~Specified~~100 ~~in Charter)~~

Delaware	001-16107	20-3538156
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)
1155 Perimeter Center West, Suite 100, Atlanta, Georgia		30338
(Address of Principal Executive Offices)		(Zip Code)

Atlanta, Georgia 30338

~~Registrant’s~~(Former ~~telephone~~name ~~number~~or former address, ~~including~~if ~~area~~changed ~~code: (678~~since last report.) ~~579-5000~~

~~N/A~~Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

~~(Former~~¨ ~~Name~~Written orcommunications ~~Former~~pursuant ~~Address,~~to ifRule ~~Changed~~425 ~~Since~~under ~~Last~~the ~~Report~~Securities Act (17 CFR 230.425)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

x Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

~~Section~~ITEM 21.01. ENTRY –INTO ~~Financial Information~~A MATERIAL DEFINITIVE AGREEMENT.

~~Item~~On 2December 3, 2010, GenOn Energy Holdings, Inc.02, ~~Results~~previously known as Mirant Corporation, a Delaware corporation (the “Company”), entered into the Third Amendment (the “Third Amendment”) to the Rights Agreement, dated as of ~~Operations~~March 26, 2009, as amended by the First Amendment, dated as of February 25, 2010, and ~~Financial~~the ~~Condition~~Second Amendment, dated as of April 28, 2010 (as amended, the “Rights Agreement”).

OnThe ~~November 5,~~Third ~~2010,~~Amendment ~~Mirant~~provides ~~Corporation~~that (Rights Agreement and the ~~“Company,”~~Rights ~~“Mirant,”~~(as ~~“we,”~~defined ~~“us,”~~in orthe ~~“our”~~Rights Agreement) ~~issued~~established athereby ~~press~~will ~~release~~terminate ~~announcing~~in ~~its~~all ~~financial~~respects ~~results~~immediately ~~for the~~prior ~~quarter~~to ~~ended~~the ~~September 30,~~Effective ~~2010.~~Time A(as ~~copy~~defined ofin ~~Mirant’s~~the ~~November 5,~~Agreement ~~2010,~~and ~~press~~Plan ~~release~~of isMerger, ~~furnished~~dated ~~hereto~~ as ~~Exhibit~~of ~~99.1~~April 11, ~~and~~2010, ~~incorporated~~ by ~~reference~~and ~~herein.~~among ~~The~~RRI ~~press release contains certain forward-looking statements~~Energy, ~~all of~~ ~~which~~Inc. ~~are~~(renamed ~~subject~~GenOn toEnergy, ~~the cautionary statement about forward-looking statements set forth therein~~Inc. ~~Except~~on ~~as otherwise provided in~~ the ~~press~~closing ~~release,~~date ~~the press release speaks only as~~ of the ~~date~~Merger) of(“RRI ~~such~~Energy”), ~~press~~RRI ~~release~~Energy ~~and~~Holdings, itInc. ~~shall~~(“Merger ~~not~~Sub”) ~~create~~and ~~any implication~~the ~~that~~Company (the ~~affairs~~“Merger ~~of Mirant will have continued unchanged since such date~~Agreement”)).

WeThe ~~use~~foregoing ~~certain~~description ~~non-GAAP~~of ~~financial measures in~~ the ~~press release~~Third ~~and~~Amendment ondoes ~~our~~not ~~earnings~~purport ~~conference~~to ~~calls.~~be ~~These~~complete ~~non-GAAP financial measures include adjusted net income, adjusted EBITDA, realized~~ and ~~unrealized~~is ~~gross~~qualified ~~margins,~~in ~~adjusted~~its ~~gross~~entirety ~~margin,~~by ~~adjusted~~reference ~~operations~~to ~~and maintenance expenses, adjusted net~~the ~~cash~~full ~~provided~~text ~~by operating activities, adjusted free cash flow and adjusted free cash flow (without MD HAA and Marsh Landing). The definitions~~ of ~~these non-GAAP financial measures, together with a discussion of~~ the ~~usefulness~~Third ~~and purpose of such measures~~Amendment, which is ~~provided in the explanations~~ attached hereto as Exhibit 994.2.1 ~~Reconciliations~~and ofis ~~each~~incorporated ofherein ~~these~~by non-GAAP measures to the most directly comparable GAAP measure can be found either in our earnings press release or in the investor presentation that we intend to utilize on our earnings conference call, which will be posted on our website prior to the commencement of the conference callreference.

~~The information contained in Item~~ITEM 2.~~02 in this Current Report on Form 8-K is to be considered “furnished” pursuant to Item 2~~01.02 COMPLETION ofOF ~~Form~~ACQUISITION ~~8-K~~OR ~~and~~DISPOSITION ~~shall~~OF not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, nor shall it be deemed incorporated by reference in any Mirant filing or report with the Securities and Exchange Commission, whether made before or after the date hereof, except as shall be expressly set forth by specific reference in such a filing or reportASSETS.

~~Section~~On December 93, –2010, ~~Financial~~pursuant ~~Statements~~to the Merger Agreement, Merger Sub was merged with and ~~Exhibits~~into the Company (the “Merger”), with the Company continuing as the surviving corporation and a wholly-owned subsidiary of RRI Energy. Upon the closing of the Merger, without any action on the part of any stockholder, each issued and outstanding share of the Company’s common stock, as well as restricted shares held in reserve under the Chapter 11 plan of reorganization for the Company, were converted into the right to receive 2.835 shares of common stock of RRI Energy, including the preferred share purchase rights granted under the Rights Agreement dated January 15, 2001, as amended November 23, 2010, between RRI Energy and Computershare Trust Company, N.A., successor in interest to JPMorgan Chase Bank, N.A., successor in interest to The Chase Manhattan Bank, as Rights Agent (the “Exchange Ratio”).

~~Item~~The 9foregoing description of the Merger Agreement and the Merger is not complete and is qualified in its entirety by reference to the Merger Agreement, which was attached as Exhibit 2.011 ~~Financial~~to ~~Statements~~the Company’s Current Report on Form 8-K filed with the Securities and ~~Exhibits~~Exchange Commission (the “Commission”) on April 12, 2010, and is incorporated herein by reference.

ITEM 3.01. NOTICE OF DELISTING OR FAILURE TO SATISFY A CONTINUED LISTING RULE OR STANDARD; TRANSFER OF LISTING.

In connection with the completion of the Merger, the Company notified the New York Stock Exchange (the “NYSE”) that each outstanding share of the Company’s common stock was converted in the Merger into the right to receive RRI Energy common stock and has requested that the NYSE file a notification of removal from listing on Form 25 with the Commission with respect to the Company’s common stock.

ITEM 3.03. MATERIAL MODIFICATION TO RIGHTS OF SECURITY HOLDERS.

Upon completion of the Merger, all outstanding warrants of the Company were converted into warrants of RRI Energy entitling the holders thereof to receive upon exercise the number of shares of common stock of RRI Energy that would have been issued or paid to such holders in the Merger if such holders had exercised the Company warrants immediately prior to completion of the Merger. Accordingly, each outstanding and unexercised warrant of the Company, upon completion of the Merger, entitled a holder to purchase 2.835 shares of common stock of RRI Energy.

In addition, the information contained in Item 1.01 is incorporated herein by reference.

ITEM 5.01. CHANGE IN CONTROL OF THE REGISTRANT.

The information required by Item 5.01 is contained in Item 2.01 and is incorporated herein by reference.

ITEM 5.02. DEPARTURE OF DIRECTORS OR CERTAIN OFFICERS; ELECTION OF DIRECTORS; APPOINTMENT OF CERTAIN OFFICERS; COMPENSATORY ARRANGEMENTS OF CERTAIN OFFICERS.

By virtue of the Merger, each of Edward R. Muller, Thomas W. Cason, A.D. Correll, Terry G. Dallas, Thomas H. Johnson, John T. Miller, Robert C. Murray and William L. Thacker, who constituted the Board of Directors of the Company prior to the closing of the Merger, ceased to be directors of the Company as of the effective time of the Merger. In addition, by virtue of the Merger, each of the named executive officers and the principal accounting officer of the Company, together with all of the other officers of the Company, ceased to hold their respective positions with the Company as of the effective time of the Merger. These actions were not a result of any disagreements with the Company on any matter relating to the Company’s operations, policies or practices.

ITEM 5.03. AMENDMENT TO ARTICLES OF INCORPORATION OR BYLAWS; CHANGE IN FISCAL YEAR.

On December 3, 2010, pursuant to the Merger Agreement, the certificate of incorporation and bylaws of Merger Sub became the certificate of incorporation and bylaws of the Company. Copies of the Company’s certificate of incorporation and bylaws are attached hereto as Exhibit 3.1 and Exhibit 3.2, respectively, and are incorporated herein by reference. In addition, on December 3, 2010, the certificate of incorporation of the Company was amended to reflect the change in name of the Company to “GenOn Energy Holdings, Inc.” The Certificate of Amendment to the Amended and Restated Certificate of Incorporation of the Company is attached hereto as Exhibit 3.3.

A copy of the certificate of amendment to the Company’s certificate of incorporation is attached hereto as Exhibit 3.3 and is incorporated herein by reference.

ITEM 8.01. OTHER EVENT.

On December 3, 2010, the Company issued a press release announcing the consummation of the Merger. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference.

ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS.

(d) Exhibits.

ExhibitNumber		Document
Exhibit No.		Description of Exhibit
99.1		Press Release dated November 5, 2010.
3.1		Amended and Restated Certificate of Incorporation of Mirant Corporation.
99.2		Explanation of Non-GAAP Financial Measures.
3.2		Bylaws of Mirant Corporation.
3.3		Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Mirant Corporation, dated December 3, 2010.
4.1		Third Amendment to the Rights Agreement, dated as of December 3, 2010, between Mirant Corporation and Mellon Investor Services LLC (incorporated by reference to Exhibit 4.4 to Mirant Corporation’s Registration Statement on Form 8-A/A filed on December 3, 2010).
99.1		Press Release of Mirant Corporation, issued December 3, 2010.

Additional Information and Where To Find It

In connection with the proposed merger between RRI Energy and Mirant, RRI Energy filed with the SEC a registration statement on Form S-4 that includes a joint proxy statement of RRI Energy and Mirant and that also constitutes a prospectus of RRI Energy. The registration statement was declared effective by the SEC on September 13, 2010. RRI Energy and Mirant urge investors and shareholders to read the registration statement, and any other relevant documents filed with the SEC, including the joint proxy statement/prospectus that is a part of the registration statement, because they contain important information. You may obtain copies of all documents filed with the SEC regarding this transaction, free of charge, at the SEC’s website (www.sec.gov). You may also obtain these documents, free of charge, from RRI Energy’s website (www.rrienergy.com) under the tab “Investor Relations” and then under the heading “Company Filings,” and from Mirant’s website (www.mirant.com) under the tab “Investor Relations” and then under the heading “SEC Filings.”

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: November 5, 2010

~~Mirant~~EXHIBIT ~~Corporation~~INDEX ~~/s/ Angela M. Nagy Angela M. Nagy Vice President and Controller (Principal Accounting Officer)~~


Exhibit No.		Description of Exhibit

3.1		Amended and Restated Certificate of Incorporation of Mirant Corporation.

3.2		Bylaws of Mirant Corporation.

3.3		Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Mirant Corporation, dated December 3, 2010.

4.1		Third Amendment to the Rights Agreement, dated as of December 3, 2010, between Mirant Corporation and Mellon Investor Services LLC (incorporated by reference to Exhibit 4.4 to Mirant Corporation’s Registration Statement on Form 8-A/A filed on December 3, 2010).

99.1		Press Release of Mirant Corporation, issued December 3, 2010.

GenOn Energy Holdings, Inc.

(Registrant)

Date: December 7, 2010

/s/ Thomas C. Livengood

Name: Thomas C. Livengood

Title: Senior Vice President and Controller

Filing Compare · MIRANT CORP