Updated at 3:55 p.m. ET with new information.
Republican Sen. Mel Martinez announced his resignation today. He said he will leave office as soon as his replacement is named in order to pursue a life in the private sector.
The senator had already announced he would not seek re-election next year.
"My priorities have always been my faith, my family and my country and at this stage in my life, and after nearly 12 years of public service in Florida and Washington, it's time I return to Florida and my family," Martinez said in a prepared statement he read at a press conference today.
Martinez said that he has no health problems or any other reasons that would force him out of office.
"There's no impending reason, it's only my desire to move on and get on with the rest of my life," he said.
Republican Florida Gov. Charlie Crist, who has announced he is running for the Senate seat in the next year's election, may appoint a replacement for the remainder of Martinez's term, according to Florida's Senate vacancy laws. Crist could appoint himself but is not expected to, a Republican source told CBS News' Political Director Steve Chaggaris.
"I have a great deal of respect for my good friend Mel Martinez. I know this decision was a difficult one for him, but I think he is doing what he believes is right for him and his family," Crist said in a prepared statement. "We will immediately begin the process of selecting an appropriate replacement to serve the remainder of Sen. Martinez's term, and I look forward to making an announcement in the coming weeks."
At today's press conference, Martinez said he had spoken with Crist earlier about his potential resignation and that he expects the governor to choose his successor in a "transparent and good process." He did not, however, give any indication of whom that person might be.
"That is the governor's decision," Martinez said. "I trust him to do a good job on that."
Possible appointments include former Republican Gov. Bob Martinez, former Crist chief of staff George Lemieux, and former Florida Attorney General and Secretary of State Jim Smith. It is expected Crist would appoint someone who will not run for the seat in 2010.
Martinez said today he would be joining the private sector but did not elaborate any further.
"I have no specific plans for my future other than it's going to be in private life," he said.
He added, however, that he would like to continue to be an active and constructive voice on public matters.