Robert Downey Jr. Negotiating Cowboys and Aliens Movie

The deal would be Downey's first since propelling Marvel Studios' "Iron Man" to $500 million-plus in worldwide loot (and growing). He next will be seen in the comedy "Tropic Thunder" in August, followed by the drama "The Soloist" in November, both for DreamWorks.

The deal would be Downey's first since propelling Marvel Studios' "Iron Man" to $500 million-plus in worldwide loot (and growing). He next will be seen in the comedy "Tropic Thunder" in August, followed by the drama "The Soloist" in November, both for DreamWorks.

Imagine Entertainment partners Brian Grazer and Ron Howard are producing. Platinum Studios chairman and CEO Scott Mitchell Rosenberg also will produce, along with DreamWorks mainstays Steven Spielberg, Alex Kurtzman and Roberto Orci. Ervin Rustemagic and Rich Marincic will co-produce.

"Cowboys & Aliens" derives from a graphic novel written by Fred Van Lente and Andrew Foley from an original idea by Rosenberg. The story centers on an Old West battle between the Apache and Western settlers, including a former Union Army gunslinger named Zeke Jackson (Downey), that is interrupted by a spaceship crashing into the prairie near Silver City, Ariz.

The story draws a parallel between the American imperialist drive to conquer the "savage" Indians with its advanced technology and the aliens' assault on Earthlings, who must join together to survive the invaders' attack.

The project has been in development at several studios during the past 10 years. Among the writers who have drafted versions of the adaptation are David Hayter ("X2: X-Men United"), Thomas Dean Donnelly and Joshua Oppenheimer ("Sahara"), Jeffrey Boam ("Indiana Jones and the Last Crusade"), Thompson Evans ("Wedlocked"), Chris Hauty ("Never Back Down") and Steve Oedekerk ("Evan Almighty").

The most recent draft by "Iron Man" and "Children of Men" writers Hawk Ostby and Mark Fergus clearly hit the right notes, as the project looks to gain its major players quickly.