Both actors are riding high at the moment, with Redmayne's projects including The Other Boleyn Girl and Savage Grace and Murphy's The Dark Knight, Hippie Hippie Shake and The Edge Of Love.
THINKFIlm is introducing the film to buyers here.
Scottish director Peter Mackie Burns, who won a Golden Bear for his 2005 short Milk, will direct from a screenplay by Scottish playwright David Harroer adapted from Ruaridh Nicoll's novel.
The psychological thriller is set in the Scottish Highlands.
Producers are David Smith of Brocken Spectre and Helena Danielsson of Hepp Films. Julie Baines of Dan Films will executive produce. Backers include Scottish Screen.
THINKFilm International is the London-based specialist sales arm of Capitol Films. Other new films on its Cannes slate are Michael Radford's La Mula and Kenneth Bowser's Down And Dirty Pictures.