According to Tracking Board, a film adaptation of Thief is in the works from Vertigo and Prime Universe.
The movie is reportedly being produced by Adrian Askarieh and Roy Lee, who are also co-producing the Deus Ex movie. Askarieh was a producer on the 2007 Hitman film adaptation, and production company Vertigo produced The Lego Movie this year.
The Thief series began with Thief: The Dark Project by Looking Glass Studios and Eidos Interactive in 1998 with an extended edition of the game, Thief Gold, releasing in 1999. It was followed by Thief II: The Metal Age in 2000, Thief: Deadly Shadows in 2004, and a reboot by Eidos Montreal earlier this year, Thief.