At 37, Mat Damon admits he feels a little old to be playing action hero Jason Bourne and has said that this third outing is destined to be the last,. Steve Pratt reports.

WHEN Matt Damon collected a best screenplay Oscar a decade ago, he probably never imagined that now he'd be concluding the film trilogy about an assassin that rivals the Bond movies for excitement.

Harvard-educated Damon and best friend Ben Affleck collected the Academy Award for their script for Good Will Hunting, in which Damon also starred and collected Oscar and Golden Globe nominations.

While Affleck has had his career ups and downs - the lowest point being his screen partnership with then-girlfriend Jennifer Lopez in the awful Gigili - Damon has worked steadily and unshowily in movies like The Departed, Ocean's Eleven and its two sequels, The Brothers Grimm, The Good Shepherd, The Talented Mr Ripley and Syriana.

The Bourne franchise, based on the character created by Robert Ludlum, is what qualifies him for Hollywood movie star status. Many of his other roles, good as they may have been, have required him to be sort of neutral. Or boring, as some have said.

"I do know what people mean when they say that," admits Damon. "But I've always played characters that have interested me, and I've got to work with directors like Soderbergh, Coppola, Spielberg, Redford, Minghella, Scorsese and then De Niro, so I've done okay. But it's fine if people think I'm boring." No-one could accuse Jason Bourne - or whoever this trained killer was before he lost his memory - of being boring as he races around the world, pursued by the bad guys and those who don't want him to remember his former identity.

"The Bourne movies gave me the creative freedom to make all those other films that I'm so proud of," he says. "Other than Good Will Hunting, which pulled Ben and me out of obscurity, the Jason Bourne role has had the biggest impact on my career. It completely changed my life."

His debut as Bourne made Hollywood sit up and take notice of the Boston-born actor. "That was when the rose-tinted lenses came off. Okay, I get it. If you're in a hit, you have a career. If you're not, the studios might think you're a nice guy, but they're not going to hang a movie on you."

With Bourne discovering who he really is, it would appear that the saga has come to a logical end. Hollywood being Hollywood, there'll no doubt be a call for a fourth film to be made.

That would require a new storyline, says Damon. "In terms of another one, the story of this guy's search for his identity is over, so there's no way we can trot out the same character."

The latest instalment of the Bourne saga includes a sniper scene in London's Waterloo Station, a rooftop pursuit in Morocco and a car chase on Manhattan's Seventh Avenue. Fight scenes were often choreographed on the spot with dialogue added as they went along, he reveals.

"It's not an advisable way to make a movie, but there's something about the chaos and this alchemy and then you bring the actors into it. All the Bourne movies have gone down to the 11th hour. It's not an advisable way to work if you want to live a long life."

HE says he felt his age - he's 37 - on this last film, particularly in the big fight scene in Tangiers. "Joey (Ansah) is like 23 years old, he was just jumping around, so excited," he says.

"He was in really good shape and I'm like, 'oh man, Joey, you gotta slow down, you're killing me'. This was the first time on a movie I realised I definitely getting older." He's a family man now. He and wife Luciana have a one-year-old daughter, Isabella, and he's also stepfather to her nine-year-old daughter Alexia from her first marriage. The family split their time between Miami and New York. To be apart when he was shooting in Morocco was something that Matt didn't like. "With a child, it's instantly not okay to be away. There's something terrible wrong if I'm not with my kid. I can see how going on the road can work, provided you have a stable base.

"So much changes in that first year. I mean she's walking around now. It happens at warp speed. I can see why when parents see babies they get that thing, 'I want another one' because the stages fly past. It's happening in front of you."

Next, he's starring as a high level corporate mole in Steven Soderbergh's The Informant, and hoping to do Imperial Life In The Emerald city about the chaotic initial American occupation of Iraq with Bourne Ultimatum director Paul Greengrass.

His aim is to have a long career, like pal George Clooney and Clint Eastwood. "Those are the careers where they're acting, writing and directing, and doing it on their own terms. I think that's the greatest," says Damon.

"I love acting and I really want to direct. At this point I just want to be smart about the work I'm doing and try to have integrity about the choices I make."

* The Bourne Ultimatum (12A) previews in cinemas today and goes on release tomorrow.