Gary Hirshberg the CEO of Stonyfield Farm has decided not to run for the U.S. Senate next year, the Boston Globe reports. Hirshberg, whose company is based in Londonderry, New Hampshire, was seen as a likely contender for the Democratic nomination in the race to challenge incumbant Sen. John Sununu. Sununu, a first term senator, is the son of the former White House chief of staff during the first Bush administration. He is considered highly vulnerable in part because New Hampshire voters ousted two long-time Republican Congressmen in the 2006 midterm elections. Democrats also won majorities in the state House and Senate last year, for the first time in decades.

Stonyfield Farm is a former Inc. 500 company and was recognized as part of Inc.'s Green 50 list last November (see ranking here.) The company, which has $250 million in revenue, sells organic dairy products including yogurt and milk. In bowing out, Hirshberg has endorsed Portsmouth Mayor Steve Marchand for the Democratic nomination. Pundits in the Granite state are also gossiping that Hirshberg will sign onto to John Edwards' presidential campaign, following a meeting between the entrepreneur and the candidate late last month.