June 19 (Bloomberg) -- Madison Square Garden LP may lose ownership of the New York Rangers as a result of its antitrust lawsuit against the National Hockey League, according to a proposed disciplinary letter filed in U.S. District Court.

Yesterday's filing in New York was part of the league's legal squabble with MSG, which has sought to keep the NHL from running the team's Web site. A federal judge in November refused to grant MSG an injunction, saying the NHL was on solid legal ground in controlling the site and those of the league's other 29 teams.

The NHL said yesterday in court documents that MSG, a Cablevision Systems Corp. unit that has owned the Rangers since 1994, violated the league's constitution in filing its suit. The NHL is seeking a judicial declaration that would let it impose internal discipline against the Rangers and MSG.

In the draft letter from NHL Commissioner Gary Bettman, the league said potential actions against MSG may include suspension or termination of membership, damages payable to the league and other teams. The NHL's board of governors would be required to approve any sanctions by a 75 percent vote.

The NHL declined additional comment.

MSG said the NHL's request underlined the need to keep the case before the court.

``Despite trying to resolve our differences privately, the league has responded with excessive fines and now threats that have nothing to do with the merits of our position,'' the company said in a statement. ``We will pursue our case vigorously and will not be intimidated by the NHL's bullying tactics.''

Madison Square Garden LP owns the Rangers, the National Basketball Association's New York Knicks, the New York Liberty of the women's NBA and the Madison Square Garden arena.

The case is Madison Square Garden v NHL, 07-cv-8455, U.S. District Court, Southern District of New York (Manhattan).

To contact the reporter on this story: Erik Matuszewski in New York at matuszewski@bloomberg.net

Last Updated: June 19, 2008 17:15 EDT