Brad Pitt in The Curious Case of Benjamin Button; Heath Ledger in The Dark Knight

The Producers Guild of America has named the nominees for its annual film awards, and there a few surprises.

The Curious Case of Benjamin Button, The Dark Knight, Milk, Frost/Nixon, and Slumdog Millionaire were the five films recognized this year. The producers of each film (Kathleen Kennedy, Frank Marshall and Cean Chaffin for Benjamin Button; Christopher Nolan, Charles Roven and Emma Thomas for Dark Knight; Brian Grazer, Ron Howard and Eric Fellner for Frost/Nixon; Dan Jinks and Bruce Cohen for Milk; and Christopher Colson for Slumdog Millionaire) will compete for Darryl F. Zanuck Producer of the Year Award.

The PGA also announced nominees for documentary features, which was a new category added last year. The nominees include Simon Chin for Man on Wire, Julie Bilson Ahlberg and Errol Morris for Standard Operating Procedure and Carl Deal and Tia Lessin for Trouble the Water. Animated feature mentions went to Clark Spencer for Bolt, Melissa Cobb for Kung Fu Panda and Jim Morris for Wall-E.

The film that has won the PGA's top award has gone on to win the Oscar for Best Picture in 12 of the last 19 years, most recently with No Country for Old Men in 2008. The nominees will be voted on by the Guild's 4,000 members, and the winners will be announced Jan. 24 at the Hollywood Palladium.