Warner Bros. TV is delaying the start of production on CBS’ blockbuster sitcom “The Big Bang Theory” because of its contract wrangling with five key stars, including Jim Parsons, Johnny Galecki and Kaley Cuoco.

The “Big Bang” actors were set to return from their summer hiatus today for a table reading of the first episode for the show’s eighth season. But with no new deals in place with the show’s core trio, plus Simon Helberg and Kunal Nayyar, Warners had little choice but to table the table reading rather than add to the tension between the studio and the thesps.

“Due to ongoing contract negotiations, production on ‘The Big Bang Theory’ — which was originally scheduled to begin today — has been postponed,” WBTV said in a statement.

Talks between Warners and the actors’ reps has been on and off since January. The offers on the table for Parsons, Cuoco and Galecki has topped the $1 million per episode mark, plus a larger sliver of the show’s backend, for a three-season commitment. “Big Bang,” from the prolific Chuck Lorre Prods., is projected to gross more than $1 billion in syndication sales for the studio, thanks to mammoth first-cycle deals with TV stations and cabler TBS and strong advertising sales.

But the negotiations have been complicated by the fact that Parsons’ team is said to be angling for a bigger payday than Cuoco and Galecki, while those two are insisting on parity with Parsons. Helberg and Nayyar are said to be unsatisfied with offers that are lower than those for the other three.

Parsons is a three-time Emmy winner for his “Big Bang” role, and he’s a two-time nominee this year for “Big Bang” and for his work in the HBO telepic “The Normal Heart.”

The back-and-forth has made for long days on the Warner Bros. lot this week. The hope is that the studio can come to terms with the thesps before too long or risk having to trim its 24-episode order for the coming season.