Megan Fox has been dropped from 'Transformers 3'.

The 24-year-old actress - who has previously compared franchise director Michael Bay to Adolf Hitler - will not reprise the role of Mikaela Banes in the third instalment, with studio Paramount Pictures refusing to confirm the reason why.

However, representatives for Megan claim it was her decision to leave the movie.

A spokesperson said: "Megan Fox will not be starring in 'Transformers 3'. It was her decision not to return. She wishes the franchise the best."

Sources have told Variety another actress will be cast as Shia LaBeouf's love interest in the movie.

John Malkovich, Patrick Dempsey and Ken Jeong have all been confirmed for roles in the film, which is due for release on July 1, 2011.

'Transformers' and the sequel 'Transformers: Revenge of the Fallen' grossed more than $1.5 billion at the box office worldwide, making it Paramount's most valuable franchise.

Megan will next be seen in Jimmy Hayward's action thriller 'Jonah Hex' alongside Josh Brolin and Will Arnett, due for release in the US on June 18.