Stargazers will be spoiled for choice tomorrow when George Clooney and Brad Pitt open the Venice Film Festival, the world’s oldest, with “Burn After Reading.”

Directors Joel and Ethan Coen — whose “No Country for Old Men” bagged four Oscars last year — have cast Mr. Pitt as an unsophisticated gym attendant who finds a CIA agent’s memoirs on a disk and blackmails him for money. The agent is played by John Malkovich, his wife’s lover by Mr. Clooney. The film is out of the official competition at this year’s festival, the 65th, which runs through September 6 on Venice’s Lido island.

Venice will also mark the screen comeback of two onetime sex symbols now well into middle age. Kim Basinger, who 22 years ago played Mickey Rourke’s blond partner in the smoldering “9 1/2 Weeks,” is cast as Charlize Theron’s mother in Guillermo Arriaga’s “The Burning Plain,” one of 21 movies competing for the top prize, the Golden Lion.

Mr. Rourke, who took up professional boxing in the 1990s, stars in Darren Aronofsky’s “The Wrestler,” also in the competition. He learned to wrestle for the film, and did all the fight scenes himself.

Another screen sweetheart now in a maternal role is Debra Winger, who seduced Richard Gere in 1982’s “An Officer and a Gentleman.” In “Rachel Getting Married,” she plays the mother of a young woman out of rehab (Anne Hathaway) who has come home for her sister’s wedding. Jonathan Demme (“The Silence of the Lambs”) directs.

More American films would have been eligible for selection had it not been for the 100-day strike by Hollywood film and television writers that ended in February, the festival’s director, Marco Muller, told reporters last month.

Heading this year’s seven-member jury is German filmmaker Wim Wenders. The jury also includes “Rain Man” actress Valeria Golino and “The Blues Brothers” director John Landis.

French actress Juliette Binoche plays in Iranian auteur Abbas Kiarostami’s out-of-competition “Shirin.”

Other highlights include Kathryn Bigelow’s “The Hurt Locker,” about an elite bomb squad in Iraq, with Ralph Fiennes and Guy Pearce.

Italian films feature prominently at the festival, after “Gomorra” (by Matteo Garrone) and “Il Divo” (by Paolo Sorrentino) won awards at Cannes earlier this year. There are four homegrown productions in the running.

Japan’s Takeshi Kitano (“Achilles and the Tortoise”) and animation master Hayao Miyazaki (“Ponyo on the Cliff by the Sea”) are also in the competition.