Frist was considered the leading Republican contender in the open governor’s race. Several prospective GOP contenders had conditioned getting into the race on Frist not becoming a candidate.

Frist, a transplant surgeon, said he decided not to run to concentrate on teaching at Vanderbilt University in Nashville. He also cited his work on global health initiatives as well as an initiative he plans to launch to improve the state’s public schools.

“If I had run, I would have started running next week,” Frist told the Associated Press by phone from Fort Lauderdale, Fla. “Having a two year campaign would mean I would have to move all those passions totally aside.”

Within an hour after Frist’s announcement, Shelby County District Attorney General Bill Gibbons announced his candidacy for governor is moving forward.

“As governor, I will place priority on two issues – crime and schools – that pose big challenges to our state and that we must address if we are to achieve a better future for Tennessee,” Gibbons, who is running in the Republican primary for governor, said in a written statement.

Gibbons is scheduled to talk more about his bid for governor at a press conference later today.

Gibbons is not expected to be alone in the 2010 primary. Chattanooga Cong. Zack Wamp also said he would run if Frist did.

Knoxville Mayor Bill Haslam and state Senate Speaker Ron Ramsey of Blountville are also weighing bids in the GOP primary.

Possible Democratic contenders include former Memphis Cong. Harold Ford Jr., Cong. Lincoln Davis of Pall Mall, Tn. and former state House Majority Leader Kim McMillan of Clarksville.

Read more about the early look of the race for Tennessee Governor in Tuesday’s edition of The Daily News.