Carroll ended his nine-year tenure with the Trojans yesterday, leaving behind a program facing multiple woes for a lucrative deal to coach the Seahawks.

“If you know anything about me, you know I can’t pass up this challenge,’’ Carroll said.

USC quarterback Matt Barkley also said quarterbacks coach Jeremy Bates is leaving with Carroll after just one season, presumably to become the Seahawks’ offensive coordinator.

Carroll won 97 games, seven Pac-10 titles, and two national championships at USC, but the school is under a cloud of NCAA investigation and other scandals. Although the charismatic 58-year-old coach spoke glowingly of his highly successful years in Los Angeles, he jumped at the best - and timeliest - of many offers he’s received over the years to return to the NFL.

“I do not expect to ever be able to top what we just did,’’ Carroll said. “I think it’s just been a beautiful time together. It hurts to separate right now . . . but it can’t keep on going, because I can’t pass up this opportunity.’’

Carroll’s departure ends one of the most successful runs in college football history - perhaps right when it was about to become much less fun, considering the just-completed 9-4 season, USC’s worst since his first year at the school.

Carroll insisted his decision had nothing to do with the NCAA’s lengthy look into his program, denouncing rumors of a rift between him and athletic director Mike Garrett. Carroll said he thought he would be at USC “forever.’’

But Seahawks owner Paul Allen pried the former Patriots coach out of a comfortable oceanside life as one of the most popular sports figures in the nation’s second-largest media market, with numerous charity endeavors and a team that helped fill the area’s NFL void.

He’s taking along Bates, who replaced Steve Sarkisian last year. Sarkisian recruited Barkley before jumping ship to the University of Washington last year.

“It’s kind of disappointing to see them leave,’’ Barkley said. “I came to this school because I wanted to be a Trojan, and nothing about coaches leaving would change that for me.’’

Carroll’s hiring capped a busy weekend for Seahawks chief executive Tod Leiweke. Seattle fired coach Jim Mora Friday after just one season, and Leiweke spent Sunday in Hermosa Beach completing a deal with Carroll.

Late last night Leiweke said Carroll had been given “operating duties,’’ responsibilities equivalent to a vice president of football operations.

Carroll will work alongside whomever Seattle eventually names as its general manager on operations beyond coaching the 53-man roster.

Next up for Leiweke is to hire that GM, and he has at least four interviews lined up. Former Titans GM Floyd Reese, now a senior football adviser with the Patriots, is scheduled for one, along with Giants personnel man Marc Ross, Green Bay executive John Schneider, and Omar Khan, a contract administrator with Pittsburgh.

Seattle forced out president and GM Tim Ruskell Dec. 3.

Carroll was 6-10 in 1994 with the Jets and then 27-21 while twice reaching the playoffs from ’97-99 with the Patriots.

The Seahawks are in need of some major rebuilding, just four seasons after the team made its only Super Bowl appearance. Seattle went 5-11 this season.

Mora said yesterday he was “very stunned, to say the least’’ at his firing.

“I’ve never seen this happen like this before,’’ he said. “I was very stunned. I don’t know that it’s even hit me yet.’’