The stars of the hit US sitcom The Big Bang Theory have yet to ink new contracts and are believed to be holding out for $US1 million ($1.07m) an episode.
US network CBS has already green lit three more seasons of The Big Bang Theory, which airs in Australia on the Nine Network, but negotiations with actors has hit a snag.
The Hollywood Reporter says actors Jim Parsons (who plays Sheldon Cooper), Johnny Galecki (Leonard Hofstadter), Kaley Cuoco (Penny Kaley), Simon Helberg (Howard Wolowitz) and Kunal Nayyar (Raj Koothrappal) have not signed and are working together to extract a huge pay increase.
The US entertainment website quotes industry sources and says there has been no movement in the negotiations which started in September.
The eighth season of The Big Bang Theory is due to start production by the end of July.
However, the cast is not expected to follow the lead of the Modern Family cast which staged a walkout while they renegotiated their deals with studio 20th Century Fox Television.
"Multiple Emmy winner Parsons (who again is nominated this year), Galecki and Cuoco are all seeking big salary increases," The Hollywood Reporter (THR) reports.
"Sources told THR in September that the trio, who currently earn $325,000 per episode, are seeking up to $1 million per half-hour.
"They're expected to negotiate together; Helberg and Nayyar also are looking for increases and will negotiate together."
Warner Bros. Television has so far declined to comment to The Hollywood Reporter.
The contract negotiations are reminiscent of the Friends cast who secured a salary of $US1 million an episode each for the last two seasons of the hit comedy.