The film, which will be co-presented by Disney Studios, will compete directly with another Spielberg-directed film, the Paramount-Sony 3D release "Adventures of Tintin: Secret of Unicorn." DreamWorks co-chair and CEO Stacey Snider said she believed there was enough of a holiday audience for both films.

The DreamWorks slot for Aug. 12, 2011, will now be filled by "The Help," an adaptation of the best-selling Kathryn Stockett novel co-starring Emma Stone, Bryce Dallas Howard, Tony nominee and Emmy winner Allison Janney and Tony winner Viola Davis.

The Hugh Jackman vehicle "Real Steel" will also change its release date, moving up from Nov. 18 to Oct. 7, 2011.

"War Horse" is currently filming. Jeremy Irvine, Emily Watson, Peter Mullan, David Thewlis and Benedict Cumberbatch have been reported to star.

The imaginative National Theatre production of War Horse, based on Morpurgo's novel, has made its way to London's West End and will be seen at Lincoln Center's Vivian Beaumont Theater in March 2011. The play is adapted by Nick Stafford and directed by Marianne Elliott and Tom Morris.