Arnold Schwarzenegger "hated" Sylvester Stallone until they went into business together.

The action stars had animosity towards one another at the height of their success in the 1980s and 90s but when the Fubar actor was launching his Planet Hollywood restaurant chain, he was approached and asked if his rival could be part of the venture, and he realised it was time to end the "craziness" between them.

Speaking to Andy Cohen on SiriusXM's Radio Andy, Arnold, 77, admitted: "We hated each other.

"We were kind of attacking each other and doing nasty things and saying nasty things about each other and all these stupid things.

"All of a sudden, I started working with Robert Earl and Keith Parish to create the Planet Hollywood franchise, those restaurants.

"The next thing I know is I get a phone call from my lawyer, who was also Sly's lawyer, he said, 'Arnold, is there any kind of room for Sly in Planet Hollywood?' "

The Terminator actor recalled thinking: "That's actually a good idea, because it could bring us together. And I wanted that. At that point I had grown out of my craziness."

The restaurant chain launched in 1991 in New York City with the backing of the future Expendables co-stars and other famous faces, and Arnold is proud of how they "made it work".

He added: "Sure enough, we made it work.

"And Bruce Willis became part of Planet Hollywood, Whoopi Goldberg became part of Planet Hollywood, Chuck Norris… It really was kind of an international cast."

Arnold and Sylvester, 77, are now friends and recently reflected on how their rivalry was "very helpful" to both their careers.

In a joint interview for 'TMZ Presents: Arnold + Sly: Rivals, Friends, Icons', the former Governor of California said: "There's no two ways about that: He was very helpful in my career because I had something that I could chase.

"[I was] the one who started this whole thing ... by opening up my mouth, saying stupid things, being competitive."

Sylvester added: "[When Arnie] came along I was like finally, something to motivate me. Because he is, dare I say it, competition, a threat, whatever word you wanna use.

"As soon as I saw him it was like bang, two alphas hitting. If we walked into a party we'd be staring at each other for a few seconds and then 'I gotta get that guy. He didn't do anything wrong but he will.' "