Mexican clubs Toluca and Leon have expressed preliminary interest in acquiring D.C. United midfielder Ben Olsen. No formal offers have been made, but Major League Soccer -- which negotiates and owns all contracts for players on its 12 teams -- is anticipating lucrative proposals for the 22-year-old in the next few months.

Meanwhile, Northern Virginia businessman Peter Halpin has dropped out of the running to purchase the operating rights of United after emerging as the front-runner early this year, sources close to the situation said.

Halpin joined United President and General Manager Kevin Payne at two matches at RFK Stadium early this season and was said to be serious about wanting to run the club, which is valued at an estimated $25 million. A New York investment group with international ties remains a serious candidate, while Spanish tenor Placido Domingo, artistic director of Washington Opera, is interested in buying a minority share.

Halpin did not return phone calls. Payne, who is overseeing the sale on behalf of Washington Soccer L.P., said he would not comment on negotiations.

As for Olsen, MLS's rookie of the year last season, he made a strong impression playing for the U.S. national team at the Confederations Cup in Mexico this summer.

The former University of Virginia star signed a multiyear contract extension with MLS last year, but if a substantial offer is made by a foreign club and Olsen wants to go, MLS might agree. United also would be involved in the negotiations.

Penalty Kicks

RFK has emerged as the favorite ahead of Tampa's Raymond James Stadium to host the 2000 MLS championship game. An announcement is likely in the next two weeks. RFK was sold out for the 1997 final between United and Colorado. . . .

Tampa Bay forward Raul Diaz Arce, the former United star who still draws large numbers of supporters when he plays in Washington, has commented on the stabbing of a fan at RFK on Sunday while he was playing there. "I don't know what's going on with those fans," he told the Tampa Tribune. "We go back [to RFK for a game Oct. 6], and who knows what will happen? . . . It's a little scary for me."