EAST RUTHERFORD, N.J. -- Michael Strahan had what he wanted -- a Super Bowl championship to add to a résumé featuring seven Pro Bowls and two sack records. Now it was time to leave football and leave the New York Giants after 15 years in the NFL.

Four months after a stunning Super Bowl victory over the previously unbeaten New England Patriots, the 36-year-old Strahan informed Giants co-owner John Mara he was done. He will be walking away from a $4 million contract for the 2008 season.

"I told him he's been a great Giant," Mara said Monday. "He thanked me for everything the organization has done for him. I said, 'I think you've done more for us than we can ever do for you.'"

Strahan never told his coaches or his teammates of his decision. They learned of it from reporters at practice.

"I'm just finding out about it; let me get organized," coach Tom Coughlin said after a team workout.

Strahan, who has long said he wants a job in television, plans to hold a news conference Tuesday at Giants Stadium.

Tony Agnone, Strahan's agent, said the Giants offered Strahan more money in an effort to get him to play another year.