Gene Maddaus Senior Media Writer SAG-AFTRA’s master contract with Hollywood’s largest employers is due to expire in two weeks, and negotiators who have been in bargaining talks since June 7 have a lot of proposals to work through before that deadline. The time crunch has raised the possibility that the union’s talks with the Alliance of Motion Picture and Television Producers could go past the June 30 deadline, according to multiple sources who asked not to be identified. The SAG-AFTRA board has the power to call a strike starting on July 1 if no agreement is reached. That would immediately shut down all film and TV production that has not already been halted by the writers strike.