The Boston Red Sox asked a Massachusetts court to declare them owners of the baseball that first baseman Doug Mientkiewicz caught for the final out of the 2004 World Series, clinching the franchise's first championship in 86 years.

Mientkiewicz kept the ball, which may be worth $250,000, in the ensuing celebration, and only loaned it to the team to show fans this year.

The Major League Baseball club said in the lawsuit filed yesterday in Suffolk Superior Court in Boston that Mientkiewicz got the ball as a Red Sox employee, so it should be the team's property. Boston traded Mientkiewicz to the New York Mets three months after the team won the World Series in October 2004.

The Red Sox acquired Mientkiewicz during the 2004 season, and used him mostly to bolster the team's defense at the end of games. In Game 4 of Boston's sweep of the St. Louis Cardinals in the World Series that year, he caught the ball thrown by pitcher Keith Foulke to retire Edgar Renteria for the final out and give Boston its first championship since 1918.

Mientkiewicz agreed in January to lend the ball to the Red Sox for display along with the World Series trophy on a tour of New England throughout the year.

The dispute doesn't impact the value of the baseball, which could sell for as much as $250,000, said Brandon Steiner, chief executive of Steiner Sports Marketing, a sports collectables company in New Rochelle, New York.

"The value of the ball is there, or else the Red Sox wouldn't want it back,'' Steiner said in a telephone interview.

Mientkiewicz's agent Greg Landry declined to comment. Lucinda Treat, the Red Sox's chief legal officer, didn't immediately return a message.

The case is Boston Red Sox Baseball Limited Partnership v. Doug Mientkiewicz, 157140, Massachusetts Superior Court.