Arnold Schwarzenegger won't take part in the next 'Expendables' movie without Sylvester Stallone.

Arnold Schwarzenegger

Arnold Schwarzenegger

The 69-year-old actor was meant to be reprising his role as Trench in the fourth installment of the action film but it looks like the production is up in the air at the moment as the 70-year-old actor - who directed the first movie and starred in all three as Barney Ross - has quit the franchise.

Speaking to Entertainment Weekly, Schwarzenegger said: "There is no 'Expendables' without Sly. I would never do the movie without him, no."

However, even if bosses do manage to persuade him to take part in the fourth film, he's adamant he'll only accept the role if it's written properly as he didn't feel he added "value" to the third movie.

He explained: "You know, I think the first and second one were terrific. But, the third one, I thought my part was not written well. It was also not playing well in the movie, as far as I was concerned. Maybe other people believed differently. But I didn't believe that I had any value in the movie. I love the franchise, by the way. I think it's a spectacular franchise, 'The Expendables'. I think that Sly has good ideas, what he wants to do with it, and I think if they write a really good script [in] which my part is very well-developed, I would do it. If not, then I won't do it."

Although it's thought the film will begin shooting in just a few months' time, Schwarzenegger has admitted he's yet to be approached with the script and doesn't know if it'll even go ahead now.

He said: "I have not seen the script; I don't even know if there is a script, even though they want to shoot in August again, like they usually do."

The franchise was thrown into chaos last week when Stallone confirmed he would not return due to creative differences with Nu Image/Millennium chief Avi Lerner over the script and director.

Avi said previously: "We've got disagreements with Sly, but we've had them for over a year and a half. Right now, each one has opinion. We agreed on 95 per cent of things, but there are certain things in production we don't agree on. I don't think it's over, but what write whatever you want. In my opinion, it's not dead."

The 'Expendables 4' was set to reunite series staples Stallone, Jason Statham, Schwarzenegger and Dolph Lundgren - who played Russian boxer Ivan Drago in 'Rocky IV'.

Sylvester confirmed in January that a fourth movie was on the way, revealing that he had been hitting the gym ahead of the next instalment in the blockbuster action-thriller franchise.