Sienna Miller is the first star to sign on for Paramount Pictures’ 2009 feature G.I. Joe, Variety reports.

The British actress will play the film’s female lead, described as a raven-haired baroness and sexy femme fatale skilled in espionage.

Paramount, which has set a mid-February start date, has slotted the film for an August 7, 2009, release.

The story is set at Brussels-based GIJOE, an acronym for the Global Integrated Joint Operating Entity, and revolves around an international co-ed force of operatives who use high-tech equipment to battle Cobra, an evil org headed by a Scottish arms dealer.