Charles, left, who was appointed editor in January 2006, is leaving after 10 years with Newsquest-owned Herald & Times Group.

He took over The Herald editor's chair after editing its sister paper, the Evening Times, for six years. He was also consultant editor for the launch of the Sunday Herald between 1998 and 1999.

Charles is also a former president of the UK Society of Editors and member of Britain’s press watchdog, the Press Complaints Commission

He said today: "It has been a tremendous challenge to have worked on all three titles in the group, helping to launch one and editing the two others.

"In particular, it has been a privilege to edit The Herald, now celebrating its 225th year as Scotland's leading quality daily newspaper, and to work with some of the country's finest journalists during a period of great transformational change in print and online publishing.

"I remain passionate and optimistic about the role of newspapers in the multi-media age and I would now like to apply the experience I have gained over 30 years to some of the broader challenges within the media sector, both nationally and internationally."

Herald and Times Group Managing Director Tim Blott said: "Charles has been a tremendous editor and ambassador for the company. I thank him for all he has done for us and wish him every success in the future.

"We will appoint a successor in due course."