California governor Schwarzenegger has starred in all three Terminators

Terminator Salvation: The Future Begins will be the first in a proposed trilogy of films reinventing the cyborg saga.

Derek Anderson, of production company Halycon, has told industry newspaper Variety the film will be "set in the future" during "a full-scale war".

The Terminator brand is currently being revived on US television with the Sarah Connor Chronicles series.

Lena Headey plays Sarah Connor, a role previously played by Linda Hamilton in the first two Terminator films directed by James Cameron.

'Fresh new world'

Former actor Arnold Schwarzenegger, now governor of California, last played the series' robotic protagonist in Terminator 3: Rise of the Machines.

According to Variety, however, it is unclear whether he will appear in the new film.

"We've left it open for him to maybe do a cameo," said producer Moritz Borman. "The final decision will be based on his desire and availability."

Warner Brothers have acquired North American distribution rights to the fourth Terminator film, which it plans to release in summer 2009.

"The intention is to present a fresh new world and have this be the first of a trilogy," said Borman.