Megan Fox, who made her name as Shia LaBeouf's sultry love interest in the first two Transformers movies, has been dropped from the third.
Paramount Pictures said Fox's option was not picked up for part three in the blockbuster Michael Bay series.
The studio, which released the first two movies about shape-shifting machines doing battle, declined to give further details or say who would replace the 24-year-old actress.
Fox, notorious for making attention-grabbing comments to the media, engaged in a public spat with director Bay around the release of part two last summer. But, Bay later defended her and said he looked forward to working with her on part three.
In announcing Transformers 3 in October on his blog, www.michaelbay.com, he wrote: "P.S. Megan Fox, welcome back. I promise no alien robots will harm you in any way during the production of this motion picture."
Transformers from 2007 and the 2009 sequel Transformers: Revenge of the Fallen made more than $1.5 billion worldwide. Production is to begin this month on the third instalment, with a release date set for July 1, 2011, Paramount said.