Joseph Kosinski has revealed that there will be some new characters in the Tron: Legacy sequel.
The Oblivion filmmaker said that most of the cast would be reprising their roles in the as-yet-untitled follow-up to the 2010 movie.
"Absolutely, yeah. All the cast will be returning, or nearly all of them," he said, adding: "We've also got some new characters as well that I'm excited about. I'm not allowed to name them yet as it's too early."
Olivia Wilde, Garrett Hedlund, Cillian Murphy and Bruce Boxleitner are all rumoured to return.
Joseph - who wrote and directed Oblivion, starring Tom Cruise and Morgan Freeman - said work is under way on Tron 3.
"We're working on the script right now. It's a story that we've all been developing for about four years now and we're finally at the script stage, and getting very close to getting our first draft," he said.
"The film kind of delivers on the premise of Legacy but opens it up in really exciting ways so it's something that I'm really excited about."
The third Tron film is expected to be released in 2014.