YORK — The field of prospective Democratic candidates for governor in 2010 became smaller Tuesday as former state revenue secretary Tom Wolf said he wouldn't run.

Wolf, a York businessman and generous donor to other campaigns, had recently formed a committee to raise money and already hired some top campaign advisers.

Wolf instead will rejoin The Wolf Organization, a building supplies company that his family founded in 1843, as its chairman and chief executive officer.

Wolf and his partners had bought the company and 1985 and sold it in 2006. He said he has been working with the company's owners and managers to provide additional financing to help it survive the slump in the housing market.

One of several Democrats considering a gubernatorial campaign, Wolf oversaw tax collections and the state lottery for the Rendell administration for nearly two years before he stepped down in November.

"This decision was not made lightly," he said in a statement. "In the current economic climate, my first loyalty must be to my former company and its employees."

Other Democratic prospects include Allegheny County Executive Dan Onorato, Lehigh County Executive Don Cunningham, Philadelphia businessman Tom Knox and state Auditor General Jack Wagner.