For the past six years, every feature film chosen by the Producers Guild of America for its top honour has gone on to win the best-picture prize at the Academy Awards. Sunday night, 12 Years a Slave and Gravity tied for the guild's highest honour.

The rare PGA split keeps the Oscar race wide open in one of the tightest three-way battles in years, with American Hustle shut out by the producers but very much alive following a week of big showings at the Golden Globes, Oscar nominations and Screen Actors Guild Awards.

Other trophies presented Sunday night at the guild's 25th annual awards ceremony in Beverly Hills, Calif., included Frozen for animated feature and We Steal Secrets: The Story of WikiLeaks for documentary film.