Rex Features
Rourke will play an arms dealer involved with a band of expendable mercenaries who are attempting to overthrow a South American dictator. Earlier this week, Forest Whittaker agreed to star as a CIA operative.
Jet Li, Dolph Lundgren, Jason Statham and Randy Couture are also among the cast.
Rourke has previously spoken of his gratitude for Stallone, who gave him a high-profile return to the big screen in his remake of Get Carter in 2000.
Shooting is expected to start in Brazil in March.
