Matt Damon is working on a fourth installment of the successful Bourne movie franchise.

Damon and director Paul Greengrass will be developing an original script for the popular series' fourth outing - as the films have dramatized all of Robert Ludlum's best-selling novels.

Yet both are currently held up on other projects - and Damon remains cautious about reprising his physically intense role as superspy Jason Bourne.

He tells Parade magazine, "We're working on it. This time it would be from an original script rather than a book by Robert Ludlum, but the director Paul Greengrass is busy and I am too, so we'll see what happens.

"When I did the first movie I was 29 years old. I am 37 now. After a tough fighting scene, the next day you wake up and feel your body more. That's just the way it is."

(This news article provided by World Entertainment News Network)