The latest film, which was originally slated for release in 2012 is expected to see the return of actors Shia LaBeouf and Megan Fox. Co-writer of the Revenge of the Fallen film, Ehren Kruger will also work on the project.
Bay revealed on his website that he had met with George Lucas' ILM effects house in San Francisco last week and then flew with Kruger to talk about new characters with the Hasbro team in Rhode Island.
Bay commented on the site: "Well, it's official: We have a great Transformers 3 story. Today is Day One."
Both of the Transformers film so far have grossed nearly $1 billion each internationally.