'Transformers 6' is still scheduled for a summer 2019 release date even though the planned blockbuster is yet to get a director.

Optimus Prime

Optimus Prime

The fifth film in the franchise 'Transformers: The Last Knight' is the last movie to be directed by Michael Bay who will not be returning for the next sequel.

Paramount and Hasbro, who own the rights to the brand, are moving ahead with the next movie and are confident they can find the right director to helm the project and stick to their proposed release schedule.

Brian Goldner, CEO of Hasbro, told The Hollywood Reporter: "There is not a director yet, but it's certainly a date we believe we can achieve. We own several hundred characters in the mythology. People don't know much about their home planet. We're in the process of thinking about what is the next story to tell."

Bay has helmed every instalment in the franchise since the robot toys were brought to the big screen in the first movie which was released in 2007, starring Megan Fox and Shia LaBeouf.

Although he has announced he won't be returning for the sixth instalment, the director has previously stated he would like make an R-rated 'Transformers' movie.

The 52-year-old filmmaker is unsure whether Paramount and Hasbro would be keen to stray into adult territory with the franchise, but the director thinks it would be a good move, especially following the success of 20th Century Fox's 'Deadpool'.

LaBeouf quit the series following his final appearance as Sam Witwicky in third movie 'Transformers: Revenge of the Fallen' which was released in 2009.

Mark Wahlberg was drafted in for the fourth film 'Transformers: Age of Extinction' as new male lead, single dad Cade Yeager, and has kept the franchise going despite Bay's fears it would sink without LaBeouf.

Bay explained: "It was me going to [former Paramount CEO] Brad Grey saying, 'I need to have a meeting with you.' I went to Brad and said, 'This franchise is gonna die.' "

Before the planned sixth film, the 'Transformers' franchise is going to expand with an origin story based around the fan favourite Autobot Bumblebee.