`Avatar' returns to 3-D theaters worldwide on Friday

'Avatar: Special Edition', which includes 9 minutes of new footage, opens in 3-D theaters worldwide this Friday.

"I'm trying to use the technology to keep people interested and enthused about the `Avatar' universe, because it's going to be a long time before we get another `Avatar' movie done," the filmmaker said.

Cameron, 56, already has plans for the 'Avatar' sequels.

He's also got a submarine to build, cameras for the Mars rover to design, an underwater 3-D camera to upgrade and maybe even an ocean-related feature to make.

But first, he had to select and perfect new 'Avatar' footage and persuade distributor 20th Century Fox to rerelease the film theatrically in 3-D.

Cameron said there are "hundreds of thousands, if not millions" of people who wanted to see the movie in 3-D but didn't get the chance because 'Avatar' was edged out of 3-D theaters by other scheduled 3-D releases. Since then, the number of available 3-D screens has doubled internationally, he said.