Harding will continue in his role until 11 June. His successor will be announced at the ITT conference in Split (10-12 June).

The board of the ITT said it wished to express its sincere thanks to Harding for his “wise counsel” and “valuable insights”.

ITT chairman Steven Freudmann said: “Trevor is a highly regarded industry professional who has been crucial to ITT’s growth.

“On behalf of ITT and all our members, I would like to thank him for his tremendous contribution to the organisation over the past 16 years.”

Harding’s career in travel and publishing dates back to the early 1960s. He joined TTG as publisher in 1978 before moving to Reed Travel Group in 1989.

There, he was involved in changing the name of Travel News to Travel Weekly and overseeing the brand’s expansion worldwide.

Harding took over as ITT president in 2003 before his retirement in 2007. He has since held a number of non-executive director roles throughout travel.