Warner Bros. has announced the addition of Ellen Barkin to the cast of threequel "Ocean's Thirteen," adding that production on the summer 2007 pic will start on July 21.

Director Steven Soderbergh will helm the third installment of the "Ocean's Eleven" heist flicks, with the original eleven thieves -- George Clooney, Brad Pitt, Matt Damon, Don Cheadle, Bernie Mac, Casey Affleck, Scott Caan, Shaobo Qin, Carl Reiner, Elliott Gould and Eddie Jemison -- all set to return. Andy Garcia is also set to reprise his role as Danny Ocean's nemesis, Terry Benedict, although "Thirteen" will not see the return of "Ocean's" ladies Julia Roberts or Catherine Zeta-Jones.

Barkin will assume leading lady duty, according to Variety, although the plot has yet to be revealed. Producer Jerry Weintraub disclosed only that Barkin's character "gets closely involved with Damon's character."

Variety also notes that, unlike the previous two installments, "Ocean's Thirteen" will not be shot on location (as "Eleven" and "Twelve" utilized Las Vegas and Europe, respectively) but will instead use five WB soundstages in Burbank, California, which are to include a specially constructed, fully operational casino.

Confirmation of the July start date comes as sweet relief to "Ocean's" fans, as recent rumors have suggested that the hectic schedules of integral stars Clooney and Pitt, as well as the ever-busy Soderbergh, might prevent the project from getting off the ground.

Soderbergh, who has begun filming the Che Guevara biopic "Guerrilla," is also in the post-production stage on "The Good German," (which also stars Clooney) anad has at least eight other upcoming producing gigs on his plate. Clooney is currently shooting another pic, "Michael Clayton," and is coming off a decidedly active 2005. Meanwhile, Pitt has just completed "The Assassination of Jesse James by the Coward Robert Ford" and "Babel," and is signed on for two more pics within the next year -- in addition to the birth of his first child with Angelina Jolie this summer.