Cooper was writing and was attached to direct the adaptation, which is one of the most influential of King’s works.
It is unclear why Cooper left. Sources say the parting was over creative differences, while one insider says it came down to the project’s potential rating. Cooper wants an R rating, in keeping with the rawness of King’s novel, while Warners, the lead on the project, aims to make a PG or PG-13 movie.
Another source said the project’s scope is so massive that the studios are not sure how many movies are needed to cover the entire adaptation.
David Yates and Ben Affleck were previously attached as directors.
The studio is said to be moving fast to find a replacement, and the names being thrown out as possibilities range from Cary Fukunaga and Paul Greengrass to Daniel Espinosa and Denis Villeneuve.
Cooper is best known for writing and directing the 2009 drama Crazy Heart, for which Jeff Bridges won an Oscar. Out of the Furnace, which stars Christian Bale, Casey Affleck and Zoe Saldana, opens Dec. 6.