LOS ANGELES — Kevin O'Neill returned to the college ranks today when he was announced as Southern California's basketball coach, taking over from Tim Floyd.

The school announced O'Neill's hiring in an e-mail. Floyd suddenly resigned June 9 amid allegations that he paid to have O.J. Mayo delivered to the Trojans. He said he was quitting after four seasons because he no longer had enthusiasm for his job.

O'Neill is scheduled to be introduced Monday at a campus news conference.

"We're thrilled to have Kevin O'Neill as our men's basketball coach," athletic director Mike Garrett said in a statement. "I love his coaching philosophy and principles: he's a no-nonsense coach who is very detail-oriented and prepares his teams well. He stresses defense and I've always believed that defense wins championships."

O'Neill returns to the Pac-10 after serving as interim coach at Arizona in 2008 when Lute Olson took a leave of absence. He was designated Olson's permanent successor, but that plan was later scrapped and O'Neill left the program.

The 52-year-old coach was an assistant with the NBA's Memphis Grizzlies this past season. Mayo plays for the Grizzlies. O'Neill led the Toronto Raptors to a 33-49 record in 2004.

O'Neill is 171-180 in 12 seasons as a college head coach, including stints at Marquette, Tennessee and Northwestern.

He takes over a USC program that won at least 20 games and made the NCAA tournament each of the last three seasons, both school records. But all is not well with the Trojans.

"I'm very excited about this opportunity to coach at such a great institution as USC, with its tremendous athletic and academic tradition," O'Neill said in the statement. "I appreciate Mike Garrett's confidence in me. I will work my hardest to coach us to a championship level every single day. I can't wait to get started."

O'Neill will need that enthusiasm as he takes over a program under investigation by the NCAA for alleged improprieties involving Mayo, who played one season at USC before leaving for the NBA.

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.

Since the Trojans' season ended in March, starters DeMar DeRozan, Taj Gibson and Daniel Hackett, along with Marcus Johnson, declared for Thursday's NBA draft, and the Trojans have lost eight recruits.