Howard, who has starred in "Hustle & Flow," "The Brave One" and "August Rush," played Rhodes, the man who would eventually become superhero War Machine, in the first installment of the "Iron Man" franchise.

Cheadle has starred in "Ocean's Eleven" and its two sequels, as well as "Hotel Rwanda," "Talk to Me" and "Reign Over Me."

The Hollywood Reporter cited unnamed sources close to the "Iron Man 2" production as saying Howard was replaced by his "Crash" co-star Cheadle because Howard and the studio couldn't reach a deal due to financial differences.

The entertainment industry trade newspaper said Marvel Studios declined to comment on the rumored casting change.

"Tropic Thunder" scribe Justin Theroux is writing the screenplay for "IM2," while Jon Favreau is set to return as director, and Robert Downey Jr. and Gwyneth Paltrow are signed to reprise their lead roles from the first "Iron Man" blockbuster, The Hollywood Reporter said.