Guests watch as actor Brad Pitt arrives at the 18th Annual Palm Springs International Film Festival Gala in Palm Springs, California January 6, 2007.[Reuters]

Brad Pitt has signed on to join his "Ocean's Thirteen" co-star George Clooney in the Coen brothers' black comedy "Burn After Reading."

The project, which also stars Frances McDormand, centers on a CIA agent who loses the disc of the book he is writing. Like the film's title, the screenplay is shrouded in secrecy, and it was unclear what role Pitt would play.

The actor will begin shooting the film in late August.

Joel and Ethan Coen penned the screenplay, and Joel Coen will direct. Focus Features will distribute worldwide.

Pitt, whose "Ocean's Thirteen" will unspool at next month's Cannes Film Festival, recently wrapped "The Assassination of Jesse James." The "Babel" star's upcoming films also include "Benjamin Button," which he is finishing in New Orleans.