The union representing Hollywood actors said Thursday that crunch talks with studios to avert a major industry shutdown had ended without a deal, paving the way for a vote on the first actors strike in more than four decades.

The Screen Actors Guild (SAG-AFTRA), which represents 160,000 performers including A-list stars, said last-ditch talks had failed to resolve their demands over dwindling pay and the threat posed by artificial intelligence.

The union's negotiators had unanimously recommended a strike to its national committee, which was set to vote Thursday morning on whether to carry out industrial action, it said in a statement.

A "double strike" of actors and writers, not seen in Hollywood since 1960, would bring nearly all US film and television productions to a halt.

Popular series set to return to television this year would face lengthy delays. And, if strikes continue, future blockbuster films would be postponed too.

Actors are demanding better pay, and protections against the future use of AI in television and films.

"We are deeply disappointed that SAG-AFTRA has decided to walk away from negotiations. This is the Union's choice, not ours," the Alliance of Motion Picture and Television Producers said in a statement early Thursday.

Hollywood studios had called in federal mediators to help resolve the deadlock -- a last-minute move described by SAG-AFTRA as a "cynical ploy."

SAG-AFTRA represents A-list stars such as Meryl Streep, Jennifer Lawrence, Glenn Close and all members have pre-approved industrial action if a deal is not struck.

- Premieres and parties -

A strike would immediately prevent stars from promoting some of the year's biggest releases, right at the peak of the movie industry's summer blockbuster season.

In London, a premiere Wednesday night for Christopher Nolan's "Oppenheimer" was brought forward by an hour, so that cast including Robert Downey Jr., Matt Damon and Emily Blunt could attend without breaking union rules, Variety reported.

But a strike would derail the much-hyped film's US premiere, due to take place in New York on Monday, as well as a scheduled red-carpet launch this weekend at Disneyland for the new "Haunted Mansion" movie.

And the massive annual Comic-Con pop culture gathering in San Diego next week could be stripped of its stars.

Even the Emmy Awards, television's version of the Oscars, which is due to take place on September 18, is reportedly mulling a delay to November or even next year.

"We hope the ongoing guild negotiations can come to an equitable and swift resolution," said Television Academy chairman Frank Scherma, as the Emmy nominations were announced Wednesday.

- 'Swift resolution -

While the writers' strike has already dramatically reduced the number of movies and shows in production, an actors' walkout would shutter almost everything.

Some reality TV, animation and talk shows could continue.

Earlier on Wednesday, Hollywood unions representing directors, behind-the-scenes film workers and writers issued a statement of "unwavering support and solidarity" with the actors.

"While the studios have collective worth of trillions of dollars, billions of viewers globally, and sky-high profits, this fight is not about actors against the studios," it said.

Workers "across all crafts and departments" stand together "to prevent mega-corporations from eroding the conditions we fought decades to achieve," it said.

- Pay and AI -

Like the writers, who have already spent 11 weeks on the picket lines, actors are demanding higher pay to counteract inflation, and guarantees for their future livelihoods.

In addition to salaries when they are actively working, actors earn payments called "residuals" every time a film or show they starred in is aired on network or cable -- particularly helpful when performers are between projects.

But today, streamers like Netflix and Disney+ do not disclose viewing figures for their shows, and offer the same flat rate for everything on their platforms, regardless of its popularity.

Muddying the waters further is the issue of AI. Both actors and writers want guarantees to regulate its future use, but studios have so far refused to budge.