American films dominated the list of 22 selected to compete for the Golden Lion award at this year's Venice Film Festival, which takes place Sept. 1-11. Festival organizers said that a 23rd "surprise" competitor will be announced after the festival is well underway, on September 6. They gave no hint as to the nature of the surprise. Among the U.S. films entered in the competition will be Darren Aronofsky's Black Swan, which stars Natalie Portman, Winona Ryder, Barbara Hershey and Vincent Cassel and is scheduled to open the festival, regarded as the world's oldest film competition. (It was launched in 1932.) Aronofsky won the top prize at Venice in 2008 for The Wrestler. Opening night will also see the screening of a second film, Legend of the Fist The Return of Chen Zhen, directed by Andrew Lau. Other American films include Sofia Coppola's Nowhere , starring Stephen Dorff and Benicio Del Toro, and Julian Schnabel's Miral, starring Willem Dafoe and Vanessa Redgrave. The festival will also feature the world premiere of Julie Taymor's The Tempest, in which Helen Mirren plays the role of the sorcerer Prospero (renamed Prospera for the film).