FACTBOX: Possible nominees for Obama's energy secretary

(Reuters) - Several people who could serve as energy secretary in U.S. President-elect Barack Obama's administration already have been mentioned by Washington insiders, lobbyists and blog writers, including:

* U.S. Sen. Jeff Bingaman, Democrat of New Mexico, chairman of the Senate Energy and Natural Resources Committee. He advocates renewable energy and energy efficiency measures.

* Wesley Clark, retired Army general and former NATO commander who ran unsuccessfully for the Democratic presidential nomination in 2004.

* General Electric Co Chief Executive Jeff Immelt, who says government investment in environmental technologies can create green jobs.

* Ray Mabus, former Democratic Governor of Mississippi and U.S. ambassador to Saudi Arabia, the world's biggest oil producer. He served as a senior adviser to the Obama campaign.

* U.S. Rep. Ed Markey, Democrat of Massachusetts, chairman of the House Select Committee on Energy Independence and Global Warming. A long-time critic of OPEC and nuclear power, he supported higher fuel economy standards for cars and trucks.

* Dan Reicher, director of climate change and energy initiatives at Google.org. A former assistant energy secretary under President Bill Clinton, he wants more U.S. electricity generated by renewable sources and promotes plug-in vehicles.

* Pennsylvania Gov. Ed Rendell, a Democrat who has called for a $850 million state Energy Independence Fund to invest in clean energy projects and reduce greenhouse gas emissions.

* Montana Gov. Brian Schweitzer, a Democrat who is a big promoter of developing liquid fuel from coal.

* Kansas Gov. Kathleen Sebelius, a Democrat who fought efforts to allow a coal-fired power plant to expand in her state, saying it would spew more greenhouse gas emissions.

(Reporting by Tom Doggett; Editing by David Gregorio)