The studio is close to a deal with Steinbeck's estate for feature rights to his Pulitzer Prize-winning novel, which celebrates its 75th anniversary next year.
Steven Spielberg is expected to produce the film but not direct though he recently left Bradley Cooper starrer 'American Sniper' for Warner Bros, reported The Wrap.
The 1939 novel was turned into an equally celebrated film by John Ford in 1940, starring Henry Fonda as Tom Joads. Ford won the best director Oscar for the film while Jane Darwell was named the best supporting actress for her role as pragmatic Ma Joad.
Letts also adapted "August: Osage County" for the Weinstein Company, which will release the film on Christmas Day. The film, directed by John Wells, is expected to be a major awards contender. The formidable cast include names like Meryl Streep, Julia Roberts, Ewan McGregor and Benedict Cumberbatch.
Letts is also an actor and will be seen playing the role of a US Senator on 'Homeland'.
