The Lord of the Rings has won the main prize given by the Producers Guild of America (PGA), making it a front runner for this year's Oscars ceremony.
Peter Jackson directed and produced The Return of the King
The Return of the King took the Darryl F Zanuck award for best picture, adding to a string of major honours.
Ten of the 14 previous winners of the prize have gone on to scoop the Oscar for Best Picture at the Academy Awards.
Cold Mountain and The Last Samurai were among the other films also in the running for the Producers Guild gong.
Lord of the Rings director Peter Jackson was also one of the producers of the films, with Return of the King bringing an end to the trilogy.
The trilogy has become one of the most successful in movie history, with the first two instalments raking in about $1.8bn (£993m) worldwide, and the third grossing $710m (£391.9m) so far.
Television was also recognised at the PGA awards ceremony held in Los Angeles, with Six Feet Under winning the drama prize.
Sex and the City took the best comedy plaudits, while Queer Eye for the Straight Guy won the reality, game or informational series category.
TV movie My House in Umbria, featuring an star cast including Dame Maggie Smith, Chris Cooper and Ronnie Barker, collected the long-form television prize.