Pete has been leading the Mirror's digital revolution for the past three years. This was his second stint with Trinity Mirror, having previously been Deputy Editor of the Sunday People.
Lloyd Embley, Group Editor-in-Chief, said: "Pete has been instrumental in the success of Mirror Online.
"Under his leadership, our monthly unique users have risen from 45 million to a record high of 92 million, and video traffic has soared from 3 million to 40 million views per month.
"Pete's role in this cannot be understated, and although we are sorry to see him go we will maintain strong relations with him.
"On a personal level, I would like to wish him every success in his studies and for the future."
Pete said: "I've enjoyed my time immensely and am very grateful to the wonderful team at the Mirror for the success we have achieved.
"Mirror Online has overtaken Guardian Online under Ben Rankin and the UK team, and is in the Top 10 for newspaper sites in the US under Natalie Evans and the US team.
"The growth is fantastic, but it's the feedback from our readers which I'm most proud of, and the community of 195,000 registered users we have built.
"My biggest regret on leaving is that I won't be able to share in the future success I know Mirror Online will undoubtedly deliver."
An announcement in relation to Pete's replacement will be made nearer the time of his departure.
