It added that all members of the UK and Ireland board will now report into David Burling until a new managing director for Tui UK and Ireland has been appointed.
In a statement the group said that under his leadership Tui UK and Ireland "had achieved commercial success, launched two cruise ships, seen developments in the retail estate, the e-commerce programme, contact centre operations and led the business through the rebrand to Tui".
David Burling, chief executive Tui Northern Region said: “Nick has been a fantastic colleague and has continually strived to do the best for the business and all those who work for it. I want to thank him for his support and thank him for all he’s done and wish him the very best for the future.”
Longman held various leadership roles in the business since 1998, joining as head of audit for First Choice.
He later became the integration director for the merger of Thomson and First Choice in 2006 and UK distribution director in 2008, overseeing the move to direct distribution, the growth of online sales and the revitalisation of Tui’s retail estate, the group said.
Longman took on the role of managing director for the group’s UK and Ireland business at the beginning of June 2015.