Pete Carroll is leaving the University of Southern California, and the coach the school considered its top choice to succeed him is no longer available.

Several Trojans players said last night that they were informed by text message from staff that Carroll would become coach of the NFL's Seattle Seahawks.

According to a source familiar with the negotiations, the deal will be signed this morning and Carroll will be introduced as the Seahawks coach tomorrow.

Meantime, Oregon State coach Mike Riley, who had been targeted by USC as Carroll's possible successor, agreed to a three-year contract extension.

Carroll's return to an NFL sideline for the first time since 1999 has been regarded as a near foregone conclusion since Friday when it became clear that the Seahawks had targeted the 58-year-old coach to succeed the recently fired Jim Mora.

The Seahawks offered Carroll a five-year contract that would pay him nearly $33 million and give him control of the football operation.

"I'm really blessed that I got a chance to play under him for a year," USC freshman quarterback Matt Barkley said.