Ilion Animation Studios' $60m feature is currently in production and due to be complete around mid-March 2009.
Jorge Blanco is directing and Javier Abad and Marcos Martinez, who worked with Blanco on the bestselling video game Commandos, are co-directing.
Casting agents Ruth Lambert and Robert McGee are seeking A-list leads for the story of an astronaut who lands on a planet where the people are paranoid about alien invasion. Ilion Animation Studios CEO Ignacio Perez Dolset is serving as producer.
Following initial discussions between Handmade's Guy Collins and New Line president Bob Shaye the deal was closed last week between Collins, Dolset and New Line's head of business affairs and co-production Carolyn Blackwood and head of acquisitions Guy Stodel.
Handmade Films International has already completed sales to more than 30 territories.
'New Line is one of the most successful marketing forces in the business and the perfect partner to board this blockbusting animation,' Collins said.
'With Bob's team on board we are looking to see Planet 51 as one of the top box office successes of 2009, combining massive merchandising potential with its unique concept to a global market.'
'We have made an enormous effort to create this truly amazing world of Planet 51 that will put Ilion Studios at the forefront of computer-generated animation,' Dolset said.
'We are thrilled to be partnering with New Line, and with their talent and expertise are sure that Planet 51 will be a phenomenal success and a unique animation experience for cinemagoers world-wide.'
Ilion Animation Studios set up a purpose-build studio five years ago to start work on Planet 51.