By Henry K. Lee and David R. Baker, San Francisco Chronicle

FBI agents served search warrants this morning at Solyndra, the Fremont solar company that abruptly closed last week, two years after receiving more than $500 million in federal stimulus money, an agency official said.

The search is part of a joint investigation involving the FBI and the Department of Energy's Office of Inspector General, said FBI spokeswoman Julianne Sohn, who declined to elaborate.

Solyndra spokesman Dave Miller said today, "We are cooperating, that is all I can say."