The board of directors said it accepted the news with gratitude for the leading role Mr Lewis has taken and the outstanding service he has provided since he joined the company in 2010.

Colin Lewis will continue his association with Avant, serving as non-executive deputy chairman for one year following the date of his retirement.

Colin’s successor will be Mark Mitchell, who will move from his current position as chief operating officer and take up his new role on May 1.

Mark has been with the business since 2001, having joined as a trainee quantity surveyor and held many posts as he moved through the business, most notably regional managing director of the Yorkshire region and group operations officer before taking up the role of chief operating officer in 2018.

In addition, the board has announced the appointment of Scott Varley to the role of group operations officer from May 1.

Scott joined the company in 2006, and, like Mark Mitchell, has come through the Avant ranks before taking up roles of regional managing director in both the North East of England and Scotland, and more latterly as divisional managing director, covering those regions together with the Midlands.

Paul Bridges, chairman of Avant, said: “Colin has been an outstanding chief executive officer and, in leading Avant, has fulfilled the shareholders’ vision for the company, whilst creating a springboard for future growth in its chosen markets. We cannot thank Colin enough for his dedication, passion, strategies and motivation that he has given Avant over the past almost 11 years.

“Whilst Colin and his enthusiastic style will be greatly missed by the staff, board and partners alike, we wish him well in his retirement; thank him warmly for his outstanding service; and are hopeful and excited for the next chapter in the Avant story.”

Mr Bridges added: “As an integral part of his own succession plan, Colin has worked very closely with Mark, having identified his talent and potential within his first few months of joining in 2010. Since then Mark has become an important and increasingly leading part of the wider team which has delivered the transformative performance in Avant, especially over recent years.

“The skills Mark has shown alongside Colin have been integral to the success of the company and I am sure Mark will provide continuity in the implementation of our business plan of growth in the north of the UK.

“Scott has similarly played an important role in the development of Avant, bringing his very personal style of management and leadership to the benefit of those regions in which he has participated. The board is delighted with both of these appointments.”