Brian Helgeland is writing and directing the British thriller, which stars Hardy in dual roles as twin brothers and notorious U.K. gangsters Ronnie and Reggie Kray.
The Krays were arrested in May 1968 and subsequently convicted of various crimes. Ronnie Kray died in 1995, while Reggie Kray succumbed to cancer in 2000 -- just eight weeks after being released from prison on compassionate grounds.
Browning is making a deal to play the film's female lead, though details of her role were not immediately available.
While Browning is coming off Paul W.S. Anderson's poorly-reviewed action movie "Pompeii," she earned Hollywood's respect for her performances in "Sleeping Beauty," which garnered controversy at Cannes, and "God Help the Girl," a musical that was well-received at Sundance earlier this year.
She recently wrapped the indie "Shangri-La Suite" with Luke Grimes.
Browning is repped by UTA, Signpost and Catherine Poulton.