Gore, who led the NFC in rushing in his second pro campaign, was due to earn $435,000 in the upcoming season. With the extension, the Pro Bowl running back will be under contract to the 49ers through 2011 with a deal containing more than $14 million in guaranteed money.

Niners coach Mike Nolan confirmed the deal Wednesday morning at the NFL meetings in Phoenix.

''He agreed yesterday,'' Nolan said. ''He had a good day.

''It's a little early; Frank just finished his second year. But we identified somebody we want in Frank. He's a young player and we wanted to extend it and it's still very early in his career.''

Gore was the heart of the 49ers' offense last season, setting franchise records for yards rushing; for his 2,180 total yards from scrimmage; and for single-game rushing with his 212-yard performance against Seattle.

After a football career dotted by injuries, Gore started all 16 games for the 49ers last season and was selected to start in his first Pro Bowl. The former University of Miami star underwent reconstructive surgery on both knees in college, followed by major surgery on both shoulders after his rookie season with the Niners.

But Gore was remarkably durable while averaging 5.4 yards per carry last year. His low-to-the-ground running style delighted fans and frustrated defenses as he surpassed the best seasons by former San Francisco stars Roger Craig, Ricky Watters and Garrison Hearst.

The 49ers worried about their ability to retain Gore when he hired a new agent, Drew Rosenhaus, who reportedly told the team that Gore should be the NFL's highest-paid player. That won't happen, but the club reached an agreement that could keep Gore in San Francisco for five more seasons.

''He had an outstanding year,'' Nolan said. ''For us, it was not a fluke that he had such a good year. It's not like he lucked into it.''

Gore was in Phoenix on Wednesday at the league meetings while negotiations with the 49ers heated up. He didn't respond to a request for comment.