'The Vampire Diaries' hunk Ian Somerhalder - who won the Choice Male Hottie prize at the Teen Choice Awards on Sunday (22.07.12) - is favourite to play Christian, the male protagonist of the book who introduces Anastasia to the world of bondage and kinky sex, International Business Time reports.
James has chosen 'The Social Network' producers Mike De Luca and Dana Brunetti to cast the roles of the charismatic billionaire and the young college student, but no stars have officially been cast.
Kristen could team up with her boyfriend and 'Twilight' co-star Robert Pattinson for the movie after admitting she is ''dying'' to make another motion picture with the 26-year-old star.
When asked recently if she would be interested in appearing in a 'Fifty Shades of Grey' movie, the brunette beauty said: ''I haven't read the book yet, so I don't know.
''But I'm dying to make another movie with Rob. I think we're a good team, and whatever it is needs to be so ridiculously ambitious ... but I'd love to work with him again.''
Kristen looks set to face competition from Scarlett Johansson for the lead female role and Ryan Gosling and Chris Pine have also been linked with the portrayal of Christian.