Oscar winner Kevin Macdonald is directing the movie, which is being shot entirely on location in Hungary and Scotland.
The film is co-financed by Film4 with Focus Features, which holds worldwide rights excluding U.K. free TV.
The project reunites Macdonald with Jeremy Brock, the BAFTA Award-winning screenwriter of his 2006 film, "The Last King of Scotland."
Brock adapted the screenplay of "The Eagle of the Ninth" from Rosemary Sutcliff's novel of the same name.
"All of us at Focus are thrilled to be once again collaborating with our colleagues at Film4 -- their support for the most exciting voices in British filmmaking is unparalleled," Focus Features Chief Executive Officer James Schamus.