Downey had hinted in numerous interviews, including a recent segment on “The Daily Show with Jon Stewart,” in which he says his days of playing Tony Stark were over.
Marvel announced the news on their website Thursday.
Downey Jr.’s deal, negotiated by CAA, comes on the heels of “Iron Man 3′s” boffo performance at the worldwide box office. The 3D blockbuster is already the fifth highest-grossing movie of all-time with a giant $1.2 billion.
“The Avengers” director Joss Whedon recently said in an interview that he had no intention of making a sequel without Downey Jr.
“He is Iron Man,