Producer Jon Landau has denied rumours that three follow-ups to the blockbuster film were in the works.
"We [are] doing two back-to-back, but not a third," he told Courier Post.
Cameron previously hinted that a fourth film may be made at some point.
A later report by Showbiz 411 said that Sigourney Weaver would be filming three movies back-to-back, but this is now thought to have been a mistake.
Cameron has said that he is currently only interested in making Avatar films.
20th Century Fox is targeting a December 2014 release date for Avatar 2 and December 2015 for Avatar 3.