Tom Wolf, the former state revenue secretary, is the first candidate out of the gate in the 2010 race for governor.

Mr. Wolf, a Democrat who made a fortune in a family building supply business, yesterday filed the official papers that will allow his new campaign to raise money in pursuit of the Democratic nomination to succeed Gov. Ed Rendell.

His personal wealth could allow him to be one of his own biggest donors. That capability could invest his campaign with instant credibility despite Mr. Wolf's modest name recognition and relatively short public resume. The York businessman is better known within state political circles as a regular contributor to the campaigns of state Democrats. Mr. Rendell appointed Mr. Wolf revenue secretary in 2007, a post he resigned in November in anticipation of a run for office.

While saying that he would hold a more formal announcement later, the new campaign alerted reporters in an e-mailed release that Mr. Wolf had already hired Jay Reiff, a native of next-door Lancaster County, who managed Sen. Bob Casey's successful 2006 challenge to former Sen. Rick Santorum.

"I am thrilled to have the counsel of Jay Reiff, one of the best Democratic strategists in the country, and I expect to make a formal announcement in the future," Mr. Wolf said.

Handling communications for the new campaign is Sean Smith, who was President-elect Barack Obama's Pennsylvania press secretary last year. That role may not last, however, as Mr. Smith has been mentioned as a potential press secretary for the Department of Homeland Security in the Obama administration. Mr. Wolf's potential rivals include Allegheny County Executive Dan Onorato, Auditor General Jack Wagner, Lehigh County Executive Don Cunningham, and another wealthy businessman, Tom Knox of Philadelphia.

Among the Republicans mentioned as possible contenders to replace Mr. Rendell, who is constitutionally barred from seeking a third term, are Attorney General Tom Corbett; Pat Meehan, the former U.S. attorney for the state's Eastern District; U.S. Rep. Jim Gerlach; and Pat Toomey, a former congressman who just missed in a bid to wrest the GOP Senate nomination from Sen. Arlen Specter in 2004.

Mr. Wolf holds a Ph.D. in political science from MIT and served as a Peace Corps volunteer in India. He and his wife, Frances, have two daughters.