PARIS (REUTERS) - Sylvester Stallone told cinemagoers in Cannes on Friday (May 24) that he never expected to make it in the film industry due to an accident at birth that caused him to slur his words - now one of his more celebrated trademarks.

The American actor, 72, rocketed to fame in 1976 with his Oscar-winning boxing movie Rocky and went on to become one of Hollywood's biggest action stars through the Rocky and Rambo franchises.

But Stallone said when he was starting out, his speech impediment stumped film-makers and fellow actors like Terminator star Arnold Schwarzenegger.

"I didn't think I was going to (have a career in film)," Stallone said during the Cannes Film Festival, where he was invited to speak in a celebration of his career.

"When I would try to get jobs in commercials, the director would go: 'What are you saying, what language is that?' I knew it was bad when Schwarzenegger said: 'You have an accent.'"

Stallone added: "I go: 'I have an accent? Excuse me, what?' It's true. Arnold and I should open a school for speech lessons. It would be perfect."

Stallone's snarl and slurred speech are now among his widely recognised signatures.

He is also known for his muscular physique.

He also reflected on his most famous roles.

"Rambo deals with the very dark side of nature that unfortunately a lot of people live with because they feel isolated," Stallone said of the character, a Vietnam War veteran who struggles to readjust to civilian life.

"Rocky is different, he's more optimistic, he realises he is not a special man but tries to be special," the actor added.

Rocky Balboa is an Italian-American boxer from a working-class background who makes it big. Stallone's performance in Rocky, the first film in the franchise, earned him Best Actor nominations at the Golden Globes, Oscars and Baftas - though he never won.

Rambo V: Last Blood, the latest film from that series, is set for release in the United States in September.