Captain America 3 will feature Robert Downey Jr. as Tony Stark, if a report from Variety proves correct. According to sources, the actor is near to signing on for the movie, which would be based around Marvel's Civil War storyline. Downey's presence in the movie is important, given that the Civil War storyline will have Tony Stark battling against Steve Rogers ("Captain America"), making Downey an important component in the film. This would join the actor's already established presence in The Avengers: Age of Ultron and The Avengers 3.
According to Variety, Downey is in the last stages of negotiations before he agrees to join the cast of Captain America 3. This follows closely after Marvel's tweet revealing that a Civil War comicbook miniseries will be arriving in 2015 -- giving about a year before the movie hits production in early 2016.
Interestingly enough, it is being reportedly that Downey almost backed out of the film because Marvel was eyeing him for only a small role -- a total of three weeks' worth of filming. Says sources, Downey demanded a bigger presence in the film, and as a result Marvel's Ike Perlmutter ordered that Tony Stark's presence be completely removed from the script.
Ultimately, Downey's role in the film was needed for Marvel to solidify its future storyline and movie plans, and the issue was apparently worked out. Says the sources, Downey will get $40m "plus backend participation" for his role in the new Captain America movie, plus a potential bonus depending on how well the film does in theaters.