LOS ANGELES -- Tim Floyd suddenly resigned as basketball coach at Southern California on Tuesday following allegations that he gave $1,000 in cash to a man who helped steer former star player O.J. Mayo to the Trojans.
Floyd submitted a one-paragraph letter to USC athletic director Mike Garrett saying he was quitting after four seasons because he no longer had full enthusiasm for his job.
"I accept Tim's decision and wish him well," Garrett said in a statement.
The Clarion-Ledger of Jackson, Miss., first reported Floyd's resignation. He is from Hattiesburg.
The announcement follows allegations that thousands of dollars in cash and gifts were funneled to Mayo by a representative of a sports agency.
Last month, YahooSports.com reported that Louis Johnson, a former associate of Mayo's, told federal and NCAA investigators that Floyd paid to have Mayo sign with the Trojans.
"The university is cooperating fully in the continuing investigation with the NCAA and Pac-10 into all allegations of NCAA and Pac-10 rules violations at USC," Todd Dickey, senior vice president of administration, said in the statement. "The university, the NCAA and Pac-10 have jointly conducted interviews of approximately 50 witnesses. No conclusions have yet been reached. At this point, it would be both inappropriate and premature to comment further."
A person close to Floyd said Tuesday night that he was surprised by the coach's resignation, but did say in his conversations with him throughout the past few weeks that the allegations against Floyd had begun to wear on him. The person, who requested his name not be used, said that Floyd was innocent of the charge that he had given cash to Rodney Guillory, but that Floyd knew fighting the charge would take an enormous amount of effort in the coming months.
Over the past few weeks, there had been countless rumors throughout the California basketball circuit that Floyd would be out as coach, but with the decision coming from USC, not from the coach.
ESPN.com was not able to contact Floyd, and messages to USC assistant coaches weren't returned. Johnson refused to comment to ESPN.com regarding Floyd's resignation.
Floyd has never addressed the allegations involving Mayo.
In mid-May, Arizona athletic director Jim Livengood said he had asked Floyd about the reports surrounding his relationship with Mayo.
"I asked him the question," Livengood said. "He said there's nothing to that. So end of question. We didn't go any farther. We didn't need to go any farther."
If the NCAA can prove Floyd paid to have Mayo delivered to USC, that would be considered a major violation. The Trojans could be forced to forfeit victories, and they could face recruiting restrictions and lose scholarships.
USC's powerhouse football team also is under NCAA investigation because of allegations that Heisman Trophy-winning running back Reggie Bush accepted gifts and his family received free rent from would-be marketers who wanted him as a client.
Floyd's resignation is another blow to a basketball program that has had starters DeMar DeRozan, Taj Gibson and Daniel Hackett declare for the upcoming NBA draft and has lost three recruits since the season ended.
Garrett said a search to hire a new coach would begin immediately.
"As of 1 p.m. today, I am resigning as head basketball coach at the University of Southern California. I deeply appreciate the opportunity afforded me by the university, as well as the chance to know and work with some of the finest young men in college athletics," Floyd wrote in his letter to Garrett.
"Unfortunately, I no longer feel I can offer the level of enthusiasm to my duties that is deserved by the university, my coaching staff, my players, their families, and the supporters of Southern Cal. I always promised my self and my family that if I ever felt I could no longer give my full enthusiasm to a job, that I should leave it to others who could. I intend to contact my coaching staff and my players in coming days and weeks to tell them how much each of them means to me. I wish the best to USC and to my successor."
In April, Floyd spurned an offer from Arizona to fill its coaching vacancy, saying he was staying at USC. A year ago, Floyd was offered the coaching job at his alma mater Louisiana State and turned it down, saying at the time, "This is my last job at SC."
The day he met reporters to say he had rejected Arizona, Floyd said, "This is still my last job."
That day Garrett called Floyd a "tremendous asset" to USC's basketball program at a school where the nationally ranked football team dominates.
"The future is very bright here under Tim's direction," Garrett said then. "We talked today, and we expressed our commitment to each other. We are both excited about our prospects for next season, especially if we have the team we think we'll have."
On May 27, Floyd appeared with football coach Pete Carroll at a meet-and-greet for USC supporters in Irvine.
Both coaches were asked whether the school was ever going to escape the cloud of the NCAA, the Los Angeles Times reported. Floyd didn't answer.
Carroll said when he first got to USC his goal was to build a program where "everyone was coming after us. Be careful what you wish for," he said, according to the newspaper.
Floyd attended scheduled meet-and-greets May 29 and June 1, but was absent from ones on June 4 and Monday night in San Diego, the school said.
The 55-year-old coach led the Trojans to the NCAA tournament three consecutive seasons, a first in the program's history, and this year he coached them to the Pac-10 tournament title. The Trojans lost to Michigan State in the second round of this year's NCAA tournament. Overall, he was 85-50 in four seasons.
Floyd had three years remaining on his contract.
Floyd's other college stints were at Iowa State, New Orleans and Idaho. His combined record in 16 years at the college level was 328-180. He coached the NBA's Chicago Bulls from 1999 to 2002 and the New Orleans Hornets from 2003 to 2004.
Information from ESPN.com senior writer Andy Katz and The Associated Press contributed to this report.