X0303 4 2010-12-03 0 0001126294 GenOn Energy, Inc. GEN 0001464572 Cleary Anne M 1000 MAIN STREET HOUSTON TX 77002 0 1 0 0 Senior Vice President, Asset M Common Stock 2010-12-03 4 A 0 103888 A 103888 D Common Stock 5 I By spouse Stock Option - Right to Buy 8.70 2010-12-03 4 A 0 23051 A 2010-12-03 2016-01-13 Common Stock 23051 23051 D Stock Option - Right to Buy 8.84 2010-12-03 4 A 0 25463 A 2010-12-03 2016-02-17 Common Stock 25463 25463 D Stock Option - Right to Buy 13.31 2010-12-03 4 A 0 14430 A 2010-12-03 2012-03-08 Common Stock 14430 14430 D Stock Option - Right to Buy 13.06 2010-12-03 4 A 0 21860 A 2010-12-03 2013-03-07 Common Stock 21860 21860 D Stock Option - Right to Buy 3.67 2010-12-03 4 A 0 67036 A 2010-12-03 2019-03-03 Common Stock 67036 67036 D Stock Option - Right to Buy 4.66 2010-12-03 4 A 0 67522 A 2010-12-03 2020-03-11 Common Stock 67522 67552 D Warrants 21.87 2010-12-03 4 A 0 99 A 2010-12-03 2011-01-03 Common Stock 280 99 D Received in exchange for 36,645 shares of common stock of Mirant Corporation ("Mirant") pursuant to the Agreement and Plan of Merger by and among Mirant, RRI Energy Holdings, Inc. and RRI Energy, Inc., now known as GenOn Energy, Inc. (the "Merger Agreement") based on the exchange ratio in the Merger Agreement. Received pursuant to the Merger Agreement in exchange for stock options to acquire 8,131 shares of Mirant common stock for $24.64 per share. Received pursuant to the Merger Agreement in exchange for stock options to acquire 8,982 shares of Mirant common stock for $25.05 per share. Received pursuant to the Merger Agreement in exchange for stock options to acquire 5,090 shares of Mirant common stock for $37.71 per share. Received pursuant to the Merger Agreement in exchange for stock options to acquire 7,711 shares of Mirant common stock for $37.02 per share. Received pursuant to the Merger Agreement in exchange for stock options to acquire 23,646 shares of Mirant common stock for $10.40 per share. Received pursuant to the Merger Agreement in exchange for stock options to acquire 23,828 shares of Mirant common stock for $13.19 per share. Received pursuant to the Merger Agreement in exchange for warrants to acquire 99 shares of Mirant common stock for $21.87 per share. /s/ Allison B. Cunningham, Attorney-in-Fact 2010-12-07