In an internal announcement St Ives chief executive Patrick Martell said Charnock was leaving to pursue other activities, and the move is understood to be by mutual agreement.

Speaking to PrintWeek, Martell confirmed that Charnock would not be directly replaced: "The group has changed a lot in the past 12 months and we are spending less on capex than in the past."

Charnock has been with the group for 18 years, and said he would be taking time out to review his options.

"I believe there are going to be some fundamental changes in this industry and I think the skills and network I’ve built up over the years mean I have a lot to offer," he said.

Charnock has been instrumental in a number of the group’s key technology investments, including the recent spend on an integrated digital book production line at Clays that includes kit from Kodak and Muller Martini.

"I’m sad to be leaving, but pleased to be going on good terms. I’ve had some great times over the years and worked with some fantastic people," he added.

The news comes as Martell gave his first interview to PrintWeek.