Updated

The Screen Actors Guild said Saturday it will ask its members to authorize a strike after its first contract talks in four months with Hollywood studios failed despite the help of a federal mediator.

The guild said it adjourned talks with the Alliance of Motion Picture and Television Producers shortly before 1 a.m. after two marathon sessions with federal mediator Juan Carlos Gonzalez.

SAG, representing more than 120,000 actors in movies, television and other media, said in a statement that it will launch a "full-scale education campaign in support of a strike authorization."

"We have already made difficult decisions and sacrifices in an attempt to reach agreement," the statement said. "Now it's time for SAG members to stand united and empower the national negotiating committee to bargain with the strength of a possible work stoppage behind them."

The statement did not specify what led to the impasse, saying only that "management continues to insist on terms we cannot responsibly accept." A SAG spokeswoman said she would not comment further. A call to the movie producers group, known as the AMPTP, was not immediately returned.

SAG's national board has already authorized its negotiating committee to call for a strike authorization vote if mediation failed. The vote would take more than a month and require more than 75 percent approval to pass.

SAG is seeking union coverage for all Internet-only productions regardless of budget and residual payments for Internet productions replayed online, as well as continued actor protections during work stoppages

But the AMPTP said it was untenable for SAG to demand a better deal than what writers, directors and another actors union accepted earlier in the year, especially now that the economy has worsened.

Earlier this week, the producers' group said it had reached its sixth labor deal this year, a tentative agreement on a three-year contract with the local branches of the International Alliance of Theatrical Stage Employees, Moving Picture Technicians, Artists and Allied Crafts, accounting for 35,000 workers.

The stagehands alliance accepted Internet provisions that were modeled on agreements with other unions, the producers group said.

Actors in prime-time television shows and movies have been working under the terms of a contract that expired June 30, with the hope of avoiding a repeat of the 100-day writers strike which shut down production of dozens of TV shows and cost the Los Angeles area economy an estimated $2.5 billion.