The 48-year-old actor essayed the role of Iron Man/Tony Stark in "The Avengers", reported Contactmusic.
If the producers of the film agree to the demands of Downey for the two-film deal, the actor would soon become the highest best-paid actor in the history of Hollywood.
Downey's agents are said to be meeting with Marvel bosses to negotiate a new deal in the coming weeks. The actor's representatives said he may consider a guaranteed USD 100 million deal, plus an increase on the seven per cent of box office receipts that he already receives.
Kevin Feige, president of the studios, is said to want Downey to reprise his part as the superhero.