The Clone Wars takes place before the events of Revenge of the Sith

A film version of Star Wars: The Clone Wars will open in the US on 15 August, followed by a TV series in the autumn.

"I felt there were a lot more stories left to tell," creator George Lucas said. "I was eager to start telling some of them through animation."

The cartoon version takes place between events in the Attack of the Clones and Revenge of the Sith films, and features familiar faces with new characters.

The half-hour, computer-animated series is an expansion of a 2003 series of three-minute shorts broadcast on TV and the web.

'Breakthrough project'

The Clone Wars will feature such familiar protagonists as Anakin Skywalker, Obi-Wan Kenobi and Padme Amidala.

George Lucas is also developing a live-action Star Wars TV series

Dan Fellman of Warner Bros described The Clone Wars as "a breakthrough project" that would "return Star Wars to the big screen in a completely new way".

"We immediately felt that it would be a fantastic theatrical event."

Release dates for the film outside the US will be announced soon, as will broadcast details for the TV series.