The Waiting City's Claire McCarthy is attached to direct The Personal History of Rachel DuPree, about black frontier women in the American Old West.
Doubt's Viola Davis is exec producing after buying the rights to the original novel by Ann Weisgarber, with Skyfall's Naomie Harris set to star.
Su Armstrong and Brian Rosen are producing for their SixtyFourSixty banner, with Julius Tennon exec producing with Davis.
London-based GFM were shopping the film to buyers in Cannes; Idris Elba was briefly announced as being attached but dropped out.
McCarthy had a busy Cannes, with her Ophelia, starring Naomi Watts and Daisy Ridley, another hot market title.
The director, who contributed a segment to 2013's The Turning but hasn't made a feature since 2009's The Waiting City, is repped by RGM Artists in Sydney and CAA in the U.S.