BBC Director-General Mark Thompson has released an internal memo that he will be stepping down from his role after the London Olympics, although no exact date has yet been set.

He said in the statement to staff, “I’ve always been on the side of change because I believe that, in the middle of a media revolution, change is the only way of safeguarding what is so precious about the BBC. But change always brings disruption and uncertainty in its wake – and I do want to say a particular thank you to everyone who has worked with me in the difficult task of transforming the BBC. Thank you for your commitment and for your patience.”

Thompson, who took over the role in 2004, is the company’s longest serving Director-General since the 1970s. During his eight years tenure, Thompson saw programming successes like Strictly Come Dancing and Frozen Planet, but also faced pressure over the BBC’s editorial breaches in recent years.