The sides are discussing plans to tap a neutral third party to help resolve an impasse in negotiations, said sources familiar with the discussions who were not authorized to comment.

The action comes as it has become increasingly clear that the sides remain far apart on key issues over streaming pay and other matters and would not be able to secure an agreement by a Wednesday night deadline, the source said.

Representatives of SAG-AFTRA and the Alliance of Motion Picture and Television Producers could not be reached for comment.

Bringing in a federal mediator would postpone any possible strike by SAG-AFTRA during the talks for at least a week, the sources said. Union members previously authorized members to call a strike if they couldn’t reach a deal.

It’s not clear how successful a mediator would be in resolving the conflict, however. In 2007, the Writers Guild of America went on strike after a mediator tried unsuccessfully to negotiate a new contract.

The talks are being closely watched as a walkout by SAG-AFTRA would be the first against the studios since 1980 and would compound problems faced by productions as the result of the Writers Guild of America strike. WGA members have been on strike since May 2.

This is a developing story