Agreement to merge with Mirant Corporation

Sunday, April 11, 2010

Today we entered into a definitive agreement to merge with Mirant Corporation in an all-stock transaction. The combined company, which will be named GenOn Energy, will be one of the largest independent power producers in the U.S. with approximately 24,700 megawatts of capacity.  GenOn Energy’s corporate headquarters will be located here in Houston, with a portion of the Company’s commercial operations and attendant support personnel based in Atlanta.  A copy of the press release is attached for your review.

As you know, our vision is to “be the best performing, best positioned generator of electricity in competitive markets.”  This transaction is a significant step toward achieving that vision.  The combination is a true merger of equals and brings together two organizations of similar size and financial strength.  Importantly, we share a common strategic vision and a focus on operational excellence.  By merging our respective companies, we will add diversity to our generation fleet and have a stronger presence in key competitive markets.  GenOn Energy’s increased scale will also provide for a more efficient support infrastructure as well as enhanced financial strength and flexibility - both of which are important to navigate through industry cycles and fluctuations in commodity prices.

The leadership of GenOn Energy will be comprised of individuals from both RRI Energy and Mirant.  GenOn Energy’s Board of Directors will have equal representation from both RRI Energy and Mirant.  Ed Muller, the chairman and chief executive officer of Mirant, will become GenOn Energy’s chairman and CEO.  I will be the president and COO and am to succeed Ed as CEO in 2013.  The GenOn Energy executive leadership team is listed on the attached chart.  I expect additional members of the GenOn Energy leadership team to be identified within the next 60 days.  You will be provided more detail on the impact of the transaction on you personally within this timeframe as well.

I understand that you will likely have many questions. Throughout this process, I am committed to treating all employees fairly and to keeping you informed of new developments.  To that end, I would like to invite you to join me on Tuesday, April 13, at 11:00 am CT for an all-employee meeting/webcast to learn more about this transaction.  For those able to join in person, the meeting will be held at Hilton Americas in Houston.  For those of you who are unable to participate at the scheduled time, an audio webcast of the meeting will be available on the RRI intranet and a video will also be posted following the event’s conclusion.

Ed Muller will be traveling to Houston so that we can both speak with you again together.   We will host another RRI all-employee meeting in the same location on Thursday, April 15 at 2:00 pm CT. As with Tuesday’s meeting, this will be available on the intranet for those who are unable to attend in person. I also encourage you to visit www.rrienergy.com for more information on the transaction.

The close of the transaction is expected to occur before the end of the year.  Until that time, it is important that we continue to operate as two independent companies.  During this period, I ask that you focus on your day-to-day responsibilities.  For the most part, it will be business as usual.

Thank you for your hard work and commitment to RRI Energy. This is a very exciting time to be part of the RRI Energy team and I look forward to the many opportunities ahead.

Sincerely,

Mark M. Jacobs
President & CEO