Johnny Depp, Orlando Bloom and Keira Knightly are on course for a fourth Pirates Of The Caribbean movie, according to the film's writer.

Terry Rossio reveals plans are afoot to make another sequel for the hit franchise but fans may have to wait a few years to see it.

After making sequels two and three back to back, Rossio feels sure Depp and company will get the chance to ditch their sea legs for a while before returning for a fourth installment.

He tells movie news website MovieHole.net, "It's like the fourth Indiana Jones picture - there are forces in play to make it happen, and forces in play to make it not happen.

"I think we will try to write a screenplay. I can't say if we'll be able to solve the challenge of making a good fourth film, or if our screenplay will be enough to get a film made."