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By Ros Krasny
WASHINGTON, June 19 (Reuters) - The U.S. Department of Energy's number two official, Daniel Poneman, will leave the agency after more than five years, Energy Secretary Ernest Moniz said on Thursday, the second senior U.S. energy official in a week to announce his departure.
"Dan let me know he intends to step down this fall so that he and his family can move on to their next adventure," Moniz said in an email to agency staff.
Poneman, U.S. deputy secretary of energy since May 2009 and also chief operating officer, has been focused on nuclear safety and proliferation, among other issues.
He briefly served as acting secretary in 2013 before Moniz's confirmation.
"He's a 'people person,' and this quality has been a tremendous asset for the department, especially in developing partnerships internationally," Moniz said. "Dan is a great friend, colleague and public servant."
Moniz also praised a recent half-Ironman triathlon completed by his athletic deputy: "I'm sure that Dan will 'run through the tape' as he completes his marathon tenure."
Poneman was instrumental in the department's emergency response to crises including negotiations with Iran in 2009, Japan's Fukushima nuclear accident in 2011 and Hurricane Sandy, which pummeled the U.S. East Coast in 2012, Moniz added.
Last week Poneman co-chaired a meeting of the U.S.-Japan Bilateral Commission on Civil Nuclear Cooperation in Tokyo, the third in a series convened to develop joint approaches to nuclear safety and environmental management.
Poneman's departure follows news Friday that Carlos Pascual, head of the State Department's office in charge of energy diplomacy, will step down in August.
Pascual is credited with having played a key role in getting countries such as China, India and Japan to cooperate with Western sanctions on Iran.
"First Pascual. Now Poneman, Obama team losing senior/seasoned leaders with broad respect," Fred Hutchison of LNG Allies, a lobbying group devoted to expanding U.S. energy exports, said on Twitter. "Successors key."
In his email Moniz said the timing of Poneman's departure "leaves ample time for the President to nominate and for the Congress to confirm" a successor. (Reporting by Ros Krasny; Editing by Doina Chiacu, Eric Beech and Meredith Mazzilli)