Shrek goes on and on

Movie bosses at Dreamworks have hired Tim Sullivan to pen a script for a fourth Shrek film, even though a third installment of the animated hit has yet to start filming.

The Shrek regulars, Eddie Murphy, Cameron Diaz and Mike Myers, will return for Shrek 3, which is set to hit cinemas in 2007, while a Puss In Boots spin-off is planned for Antonio Banderas' feline character.