Big Bang Theory
The Big Bang Theory actors Melissa Rauch, Johnny Galecki, Kaley Cuoco, Simon Helberg, Jim Parsons, Mayim Bialik and Kunal Nayyar Getty

Actors Jim Parsons, Kaley Cuoco, and Johnny Galecki contracts expire after The Big Bang Theory season 10, but CBS entertainment president Glenn Geller is optimistic about getting all the fan- favorite actors back for season 11.

Geller told Variety at the Television Critics Association winter press tour, "We are in negotiations, but it is definitely business as usual. We are guardedly optimistic that we will make a deal."

More from IBTimes UK

Geller also revealed that there is no timetable to complete negotiations with the actors to continue on show. When asked if the show could continue without any of the three lead actors, Geller said, "We want to get them all back. That's the goal."

When Parsons, Galecki and Cuoco last renewed their contracts in 2014, they each secured a fee of $1 million per episode for three 24-episode seasons. Back in 2015, showrunner Steve Molaro dished on show's renewal chances after season 10. Molaro told The Hollywood Reporter, "The reality is that maybe season 10 is the ending point. The real answer is I don't know and all I can do right now is go episode to episode and try to make each one the best that we can. There's still so many episodes to go. Even if hypothetically season 10 was the end, I wouldn't be focusing on that yet. That seems like something that would be dealt with way down the line."

"I can't speak to the future or on behalf of the cast or where we'll be then but it's certainly possible that it could go past that [season 10]." he added.

However, co-creator Chuck Lorre said the idea of season 10 being the last is a ridiculous question. "I never imagined nine [seasons] and here we are. I'm not going to presume to know how many years this has because it's ridiculous for me to guess."

Lorre also added, "It's already gone beyond my wildest dreams so anything beyond this ... as long as everybody is having a good time and we're making a show we're proud of ... then it's worth continuing."

The Big Bang Theory season 10 airs every Thursdays on CBS Network.