LOS ANGELES, USA - THE US Screen Actors Guild said on Sunday its board has voted to ask that a federal mediator be brought into labour contract negotiations.

SAG said the mediator may be asked to send a strike authorisation referendum to members if the arbitration process fails.

A strike authorisation would require 75 per cent approval of members who vote.

'We hope mediation will help move this process forward,' Screen Actors Guild's national president, Mr Alan Rosenberg, said in a statement.

Talks with Hollywood studios broke off on June 30 when the Alliance of Motion Picture and Television Producers presented SAG with a 'final' offer, hours before the old contract lapsed.

The union also said four new members have been added to its national negotiating committee - two from the Hollywood division, one from the New York division and one from the regional branch division.