SAG-AFTRA and the Alliance of Motion Picture and Television Producers representing the studios said they agreed to extend their current contract negotiations until 11:59 p.m. PT on July 12.
The contract had been set to expire Saturday night and SAG members have already authorized a strike.
Both sides have agreed to negotiate under a media blackout.
The Writers Guild of America is already on strike and a work stoppage by the actors would put additional pressure on the studios.
Like the writers, actors are concerned about how they will be compensated as the TV industry becomes increasingly digital.
With the writers on strike, late-night talk shows are out of production and new fall primetime network shows are likely to be delayed.
The Directors Guild of America reached agreement on a new three-year deal with AMPTP three weeks ago.