Matt Damon has sparked hopes of a third sequel to the hit secret agent Jason Bourne drama - but said it won't follow the storyline of Robert Ludlum's third novel.

"We'll probably do that in about a year and a half. We're all signed on in principle, in the sense that we've all agreed that we want to do it, but we're not going to do it unless we have a great script," the star was quoted as saying by Sky News.

The first film "The Bourne Identity" was a big hit. Last year's sequel "The Bourne Supremacy" won best film at the Empire Awards.

"If we do make a third one, we want to make it as good as the first two. And if we can't do that, then we're going to have to let it drop."

The third film, he said, will not follow Ludlum's "The Bourne Ultimatum", in which Jason Bourne faces his nemesis Carlos The Jackal.

"Yeah, all that stuff with Carlos being actually caught. It's kind of a Cold War story. We're essentially retaining the title."