McLean’s departure now leaves Kate Bosomworth, who joined after her agency KTB PR was acquired by Speed last July, as sole MD.
The pair became joint MDs after the departure of Stephen Waddington and Steve Earl last September.
McLean was previously deputy MD and responsible for leading Speed’s corporate offering. He also played a key role in its technology practice.
Before his time at Speed, he oversaw marketing for the launch of defunct solar energy firm Ownergy and also spent eight years at Hotwire PR.
Speed confirmed that McLean had left the agency on Friday but declined to comment further. McLean could not be reached for comment.
It is not currently known whether McLean has a role to go to or if he will be directly replaced at the agency.