Sony Pictures Worldwide Acquisitions Group has picked up U.S. distribution rights for the CG-animated kidpic “Planet 51.”

TriStar Pictures will release the film, which features the voices of Dwayne Johnson and Jessica Biel, on Nov. 20, 2009.

Alien adventure comedy centers on an astronaut who lands on Planet 51 thinking he’s the first to set foot on it. To his surprise, he discovers it’s inhabited by little green people who live in a white picket-fenced world reminiscent of 1950s America. Film is produced by Ilion Animation Studios.

Justin Long, Seann William Scott, Gary Oldman and John Cleese round out the voice cast.

New Line previously bought domestic distribution rights for the $50 million plus-budgeted film and had touted it as it as its first-ever CG-animated feature. After New Line was folded into Warner Bros. in February, “Planet 51″ became the domain of Warners and was set to be released by the studio in summer 2009.

Sources said Warner decided to let the pic go after the producers insisted on a November release, when Warner is releasing its sixth Harry Potter pic.

Ignacio Perez Dolset and Guy Collins are producing “Planet 51.” Peter Graves, Michael Ryan and Jose Rodriguez exec produce.

HandMade Films International is handling worldwide sales on the film. A “Planet 51″ videogame is being developed by Ilion.

“We could not ask for a more ideal partner,” said Guy Collins, chairman of HandMade Films Intl. “Sony is perfectly positioned to maximize the film’s box office potential.”