Paramount is parting ways with Megan Fox on “Transformers 3.”

A studio spokeswoman disclosed Wednesday that Par has decided against picking up Fox’s option to star as Mikaela Banes in the third installment, but declined to elaborate.

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.

Bay’s directing from a script by Ehren Krueger with the storyline kept under wraps. Working title is “Transformers 3.”

Pic, produced by Don Murphy, Tom DeSanto, Lorenzo di Bonaventura and Ian Bryce, is set to open July 1, 2011. Steven Spielberg is exec producing along with Bay, Brian Goldner and Mark Vahradian.

Patrick Dempsey, Frances McDormand, John Malkovich and Ken Jeong have signed on to the project. Thesps Kevin Dunn and Julie White will return in the roles of Ron Witwicky and Judy Witwicky.

“Transformers” is Paramount’s most valuable franchise, particularly since the studio is the sole financier. The first “Transformers” grossed $709.7 million worldwide, followed by $836.4 million for last year’s “Transformers: Revenge of the Fallen.”

Initially, Bay had wanted to take a longer break before lensing the threequel, but ultimately decided to meet the studio’s summer 2011 release date.

Fox will be seen next in Warner’s supernatural Western “Jonah Hex” opposite Josh Brolin. “Hex” opens June 18.

Fox’s PR reps told the People.com site Wednesday that Fox had made the decision not to return, adding, “She wishes the franchise the best.”