Disney is preparing to enlarge the Star Wars universe with a series of spinoff movies centred around alternate characters.

In an interview with CNBC, Disney Co. chief executive Bob Iger confirmed work had started on the spinoffs, which will be released in the same six-year period as new trilogy that starts with Star Wars: Episode VII in 2015.

"We are in fact working on a few stand-alone films," Iger said. "(Lawrence) Kasdan and Simon Kinberg are both working on films derived from great Star Wars characters that are not part of the overall saga. So we plan to make Star Wars VII, VIII and IX over roughly a six-year period of time starting in 2015. But there are going to be a few other films released in that period of time, too."

Iger refused to say which characters would be at the centre of the new films. Likely candidates include Yoda, bounty hunter Boba Fett and groups of Jedi-trained warriors who may have had minor roles in previous movies.

Kasdan wrote the screenplay for two Star Wars films, 1980's Episode V — The Empire Strikes Back and 1983’s Episode VI — Return of the Jedi. Kinberg, who scripted X-Men: The Last Stand, will be working on his first Star Wars film.

Disney confirmed in January that it had hired Lost creator J.J. Abrams to direct the first of a new trilogy of films — Star Wars: Episode VII — based on the universe created by George Lucas.

Disney bought Star Wars maker Lucasfilm last year for more than $4 billion US.