Oldham said: "The three-and-half years that I have spent with UPM have been both interesting and challenging, and I hope you agree that we have a tremendously committed and capable group of professionals supporting the business in the UK.

"Nevertheless I have decided to take an exciting opportunity outside the paper industry and look forward to fresh challenges in a new market.

"I would like to thank you for your support to both me and UPM over the last few years."
Oldham started in the role in July 2008, having been business general manager for International Paper’s European papers division.