This from People Magazine:
“Megan Fox will not be starring in Transformers 3," reps for the actress, 24, tell PEOPLE. "It was her decision not to return. She wishes the franchise the best.”
Variety states:
Sources close to the production indicated that Par and director Michael Bay want to take the storyline in another direction and plans to cast another actress as the love interest for star Shia LaBeouf, who plays Sam Witwicky. Those sources indicated that Fox's ouster was un- related to a September interview with a British magazine in which Fox compared Bay with Adolf Hitler.
That didn't take long for another round of feuding for Fox and director Michael Bay.
Now, before any ink has had a chance to dry, several replacements are already moving ahead.
The Wrap is reporting that:
"Prince of Persia" star Gemma Arterton is the front-runner to replace Megan Fox in "Transformers 3," TheWrap has learned.
An individual close to the casting process says the actress has already had discussions with Bay about the coveted role. Other possible replacements for Fox include models Bar Rafaeli, Miranda Kerr and Brooklyn Decker.
Rafaeli and Kerr have already read for the movie. Decker, whose prime experience has been as a swimsuit model, does have some guest starring TV roles but Arterton's acting experience gives her a sizable advantage over all three.
Gemma Arterton
Bar Rafaeli
Miranda Kerr
Brooklyn Decker