SAG-AFTRA and advertisers have once again decided to extend the expiration date of their current contracts as they hash out successor agreements.

The performers’ union and the Joint Policy Committee, which bargains on behalf of advertisers and advertising agencies, together pushed the conclusion of their current deals through April 11. The deals had previously been set to expire by the end of the day on Friday.

The union explained on Friday that the move was intended “to facilitate the continuation of productive negotiations,” perhaps nodding to the fact that if the parties kept negotiating under an expired contract, SAG-AFTRA could threaten a potential strike.

The move comes as the production of commercials, long a crucial source of employment for industry workers, is lagging in L.A. compared with recent years. An overall downturn in production work in the region has sparked the “Stay in L.A.” movement, aimed at supporting favorable...