'The Big Bang Theory' cast demands salary hike

Stars of the popular show "The Big Bang Theory" are demanding a payrise of $1 million per episode before they sign their contracts for the upcoming eighth season.

Jim Parsons, Johnny Galecki, Kaley Cuoco, Simon Helberg and Kunal Nayyar are currently in negotiations with Warner Brothers TV as they are determined to receive a similar wage to the cast of "Friends", which came to an end in 2004, according to Deadline, reports contactmusic.com.

Parsons, Galecki and Cuoco all currently earn a reported $325,000 per episode, but a rise in their pay would make them the highest paid actors on US television, beating the likes of Ashton Kutcher and Jon Cryer from comedy "Two and a Half Men".

Filming could face weeks of delay if an agreement on wages isn't reached soon, as the eighth season is expected to go into production later this month.

The network recently announced that the hit programme will continue for another three seasons, which means it will stay on screens until at least 2017.