Bulls will sign Pistons' Ben Wallace to Bulls

CHICAGO -- Ben Wallace is crossing Lake Michigan, staying in the same division and bringing his ferocious rebounding and defensive skills to a young team counting on him to be a major force in building a championship contender.

The four-time defensive player of the year, Wallace is leaving the Detroit Pistons and joining the Chicago Bulls, according to a source within the league. The contract won't become official until July 12.

Wallace is going from a team that went 64-18 in the regular season to one that was 41-41. Disappointed with the Pistons' initial offer to keep him, he agreed to a deal from the Bulls for four years that is reportedly worth $60 million.

"You get a chance to sign the deal of a lifetime. It's tough to let it go," Wallace told the Detroit News.

Wallace, at 6-foot-9, helped Detroit advance to four straight conference finals -- the first team to do so since the Bulls of the early 1990s. The Pistons won the title two years ago, lost to San Antonio in the championship round in 2005 and were beaten by the Heat in the Eastern Conference finals this season.

A day after losing Wallace, the Pistons reached an agreement with free-agent center Nazr Mohammed on Tuesday, according to an anonymous source.

Mohammed started in 30 games last season for the San Antonio Spurs, averaging 6.2 points and 5.2 rebounds. The 6-foot-10, 250-pound center will likely replace Wallace in the starting lineup.