The 70-year-old Democrat has spent four decades in public service. Along the way he had three failed runs for U.S. president.
In the June 2010 Democratic primary, Brown, the former mayor of Oakland, would likely go up against two big-city officials: San Francisco Mayor Gavin Newsom, 41, and possibly Los Angeles Mayor Antonio Villaraigosa, 56, the Los Angeles Times reported Monday.
"I have a very strong record in every office I've held of new ideas and bold moves," Brown said.
Neither Brown nor Newsom have formally announced their gubernatorial intentions. Lt. Gov. John Garamendi, 64, is the lone declared candidate in the race.
"The question that I think Californians will have to come to grips with is, does California need the same governor in 2011 that it had in 1975?" said Newsom strategist Garry South.
Republican Gov. Arnold Schwarzenegger can't run for re-election in 2010 because of term limits.