Hollywood's television and film writers will go on strike, leaders of their union told thousands of guild members who had gathered Thursday night at the Los Angeles Convention Center.

Negotiators for the Writers Guild of America said they would notify members by e-mail Friday afternoon of when the walkout would occur, according to people present at the meeting.

A strike would destabilize Southern California's signature industry and mark the first time in two decades that writers had walked off the job.

Thursday night's rally of more than 2,000 film and TV writers occurred a day after talks on a new three-year contract with their employers broke down amid disputes over DVD residuals and pay for shows distributed over the Internet.

The union's board of directors will formally ratify the strike plans at a meeting Friday at 10 a.m. at the guild's West Coast headquarters in the Fairfax district.