Robert Downey Jr for Captain America 3
Robert Downey Jr is said to be on the verge of signing up to reprise his role as Iron Man in 'Captain America 3'
Robert Downey Jr is in final negotiations to star in 'Captain America 3'.
The 49-year-old actor is set to reprise his role as Tony Stark/Iron Man in the third instalment of the popular comic book series, which is set for spring 2016 release.
Robert - who will also appear as the superhero in 'The Avengers: Age of Ultron' next summer and subsequently, in 'The Avengers 3' - is said to be on the verge of signing a deal to suit up as the character in the currently untitled Marvel production.
According to Variety.com, Robert's Iron Man is to play a vital role in the action adventure, which has a civil war storyline, and will see his character war against Captain America's alter-ego Steve Rogers, who is played by Chris Evans.
The plot sees the pair clash over the Superhero Registration Act - which forces superheroes to reveal their identifies to the US government - an idea supported by Iron Man but despised by Steve Rogers.
Although Marvel and Robert are yet to confirm the news, the actor recently hinted at reprising his role in a new comic book blockbuster.
He said: "I know there are going to be a bunch more Marvel movies and they have big ideas of how to do it best and [they're] in the middle of negotiation."