Los Angeles-based Fantastic Films International has taken on international sales and distribution rights to A Fox's Tale.
The animated feature from Hungarian director George Gat was co-written with Peter Doka.
Gat's Dyn Entertainment is producing with Bill Chamberlain's Pinewood-based UK outfit Parallel Pictures.
The voice cast will include Freddie Highmore, Bill Nighy, Miranda Richardson, and Sienna Miller.
Production started in June 2005 and the character voices were recorded at Pinewood in August 2008.
Mike Moran is scoring the film and writing original songs.
The film is about a young fox whose world is turned upside down when his father is captured and forced to join a circus - the young fox recruits some human friends to try to free his dad and the circus' other animals.
Executive producers are Konel Sipos, Laszlo Wolf, Zsofia Kende and Andras Kalman. The associate producer is Lee Chamberlain and Gillian Hawser handled casting.
Fantastic Films International has also recently worked on Spirit Of The Forest and Agent Crush.