Renee Zellweger is set to make her directorial debut with '4 1/2 minutes'.

The 'Bridget Jones' Diary' actress is to work both behind the lens and star in the comedy, opposite Johnny Knoxville.

The Script is based around the life of stand-up comedian Dov Davidoff, and follows lead character Jimmy Bennett - played by Johnny - whose life isn't working out until he takes the job of looking after the genius son of P.J. Andersen, Renee's character.

The story take place in New York and production has been scheduled to start in February.

The film is written Anthony Tambakis, who also penned the screenplay for 'Warrior'. It will be financed by PalmStar Media Capital with K5 International introducing it to potential buyers at Toronto film festival.

K5's Carl Clifton said: ''Renee Zellweger is unique. She's one of the very finest and highest-profile comic actresses working today but she has an amazing range too and, as this film and the actor/director role she is taking on it will show, she is also is one of the industry's most versatile and brightest talents.''