Talks broke down again last week after two days of negotiations involving a federal mediator, and the hockey season is in jeopardy.
The sides haven't been in touch with each other for several days since the NHL filed a class action suit Friday in U.S. District Court in New York, seeking to establish that its lockout is legal. In a separate move, the NHL filed an unfair labour practice charge with the National Labor Relations Board, claiming the players' association has bargained in bad faith.
The NHL said it believes the union's executive board is seeking authorization to give up its collective bargaining rights, a necessary step before players could file an antitrust lawsuit.
All games through Dec. 30 have been cancelled by the NHL.