Just hours before the current contract expires, the Alliance of Motion Picture and Television Producers (AMPTP) offered performers a three-year deal.

They said the offer was worth more than $250m (£125m) and addressed actors' key concerns over revenue from new media.

The Screen Actors Guild (SAG) said the offer did not appear promising.

SAG executive director and chief negotiator Doug Allen said the body were studying the 43-page proposal, adding in a statement: "This offer does not appear to address some key issues important to actors."

'Seriously threatened'

A follow-up to the 100-day Screen Writers Guild strike that damaged film and TV production earlier this year is the sequel no Hollywood studio boss wants to see, say analysts.

The AMPTP said in a statement: "Our industry is now in a de facto strike, with film production virtually shut down and television production now seriously threatened."

The studios group said it had presented its final offer to SAG, the main union of US film and TV actors, on Monday after 42 days of negotiations on a new labour contract.

The AMPTP warned the consequences of a strike "would be enormous," and that SAG's 120,000 members would lose $2.5m (£1.25m) a day in wages.

The two sides agreed to meet again on Wednesday to discuss the industry's proposal.

SAG is also contesting a deal reached with studio bosses by its smaller sister acting guild - the American Federation of Television and Radio Artists (AFTRA). SAG believes that deal undermines its own bargaining position.

BBC