HAINES CITY, FLA. ? Mike Sweeney, the power-hitting first baseman the Kansas City Royals hope to make the cornerstone of their future, agreed Friday to a $55 million, five-year extension through the 2007 season.

Sweeney gets $8 million this year, the final season of a $13 million, two-year contract, and was eligible to become a free agent after the World Series. He had said he would not negotiate once the season starts next week.

“My representatives said on the free market I’d probably be worth $14, $15 (million a year), somewhere around there,” Sweeney said. “But to me, it’s not about the money. It’s about being fair, not trying to get the most.

“For me this is the right place. I wrote on a piece of paper the pros and cons, and the pros outweighed the cons to stay in Kansas City. It’s not about money, but having peace in your heart. I have peace in my heart to sign this contract.”

The new deal can be terminated by Sweeney if the Royals do not have a .500 or better record in either the 2003 or 2004 season. It contains a limited no-trade clause, and if Sweeney does accept a trade, the average yearly salary for the remainder of the contract would increase to $12.5 million.

Signing Sweeney, the Royals’ best and most popular player since Hall of Famer George Brett, enables the Royals to avoid an image problem.

Fans have already been suspicious of new owner David Glass’ commitment after two other players, outfielders Johnny Damon and Jermaine Dye, failed to sign longterm deals and were traded to Oakland.