The family-owned UK liquor retailer, Unwins, is looking for a new chief executive to succeed David Wetz, who has stood down unexpectetdly, and for the first time in the company's 160-year history, looks set to appoint someone from outside to the top job.

Unwins, which operates 420 off licences and has annual sales of around £130m, is owned by 90 family shareholders.

Since he took up the post of CEO a year and a half ago, having already been with Unwins for 15 years, Wetz has instituted a number of modernising initiatives at a company once renowned for a somewhat old-fashioned approach to retailing. "Unwins has sweated blood and tears," Wetz said in a letter to staff. "The company has a ferocious appetite for change but now the business need is for the change to accelerate and be fed in a different way."

It appears that Wetz's departure is preparing the way for the arrival of an external CEO who can bring in new thinking and accelerate the development and modernisation of the company. Wetz said that his departure "paves the way for a new non-family appointee to the post, bringing the necessary professional retail experience essential for the successful future development of the business".

Non-executive deputy chairman, Michael Lunn, who was formerly with Scotch whisky producer, Whyte & Mackay and is the only non-family member on the board of directors, has taken on a temporary executive role until a successor to Wetz has been appointed.