Brown to announce California governor run Tuesday

OAKLAND, California (Reuters) - California Attorney General Jerry Brown will try to reclaim the state's governorship, formally announcing his candidacy on Tuesday, a source close to the campaign said.

Brown, who served two terms as governor starting in 1975, is virtually guaranteed to get the Democratic nomination in the race to lead the most populous U.S. state, with no major contenders for the nomination. Candidates must formally announce their plans by March 12.

Brown, 71, a liberal once nicknamed "Governor Moonbeam" would face off against Republican Meg Whitman, the former chief executive of eBay Inc., or state Insurance Commissioner and former Silicon Valley entrepreneur Steve Poizner. The winner will replace former actor Arnold Schwarzenegger.

Whoever wins the November election will have a tough job, as the state battles with double-digit unemployment that is expected to last years, a prolonged budget crisis, and tries to address major problems such as an inadequate water system.

Whitman leads Poizner in polls for the Republican nomination, but both lag Brown, according to Field Poll. However, Brown's lead has dropped by half, to 10 percentage points over Whitman, in a late January poll. Whitman has deep pockets to wage an expensive campaign.

Term limits were passed after Brown left office as governor, leaving him open to run again.

Brown ran unsuccessfully for the Democratic presidential nomination in 1976, 1980 and 1992. He served as mayor of Oakland from 1998 to 2006.

(Writing and reporting by Peter Henderson; Editing by Bill Trott)