TALLAHASSEE, Fla. -- Gov. Charlie Crist on Sunday announced three more candidates for Republican U.S. Sen. Mel Martinez's job.

According to a statement from Crist's office, former U.S. Reps. Mike Bilirakis, Lou Frey and Clay Shaw have been asked to fill out a questionnaire for the position.

Crist, also a Republican, expanded his list of candidates after meeting with party leaders over the weekend in Orlando. On Friday, he had said he didn't expect to ask anyone else to apply for the job. However, he also said, "You always keep the option open."

The candidates previously announced were: state Rep. Jennifer Carroll, former Jacksonville mayor and University of North Florida Prisident John Delaney, former Crist chief-of-staff George LeMieux, former U.S. Attorney Roberto Martinez, lobbyist Jim Smith, former state Sen. Dan Webster, and U.S. Rep. Bill Young.

All 10 potential appointees are all Republicans.

Bilirakis served 12 terms in Congress until he was succeeded by his son, U.S. Rep. Gus Bilirakis, in 2006.

Shaw lost a costly, fierce bid for a 14th term to Democrat Ron Klein in 2006. He blamed his defeat on the timing of Donald Rumsfeld's resignation as defense secretary, saying Rumsfeld could have saved him and other House Republicans by leaving sooner.

Frey served as a state chairman of Bob Dole's presidential campaign. In recent years, he joined former Gov. Bob Graham in lawsuits challenging the Legislature's authority over tuition and fees at state universities.

Martinez announced earlier this month that he would leave office more than a year before his first term expires in January 2011. Crist is running for the position but says he will not appoint himself to fill the unexpired term.

Crist had said he would likely choose a replacement this week so there would be time to prepare before the Senate returns from recess Sept. 8.

Crist faces former House Speaker Marco Rubio in the Republican primary. U.S. Rep. Kendrick Meek is the only major Democrat in the race, though U.S. Rep. Corrine Brown has formed a Senate exploratory committee.