THE entrepreneur who helped turn Wolfson Microelectronics from a university spin-out company into a listed stock market success story is leaving the business.

David Milne has spent 28 years with the Edinburgh semiconductor-maker after co-founding it with Jim Reid in 1984.

Mr Milne spent the best part of 23 years as chief executive and managing director – the business was listed on the London Stock Exchange in 2003 – before stepping down in 2007.

During his time at the helm, alongside executives such as finance director George Elliott, Wolfson's audio chip products were carried in consumer electronic devices such as Microsoft's Xbox and Apple's iPod.

In the past five years Mr Milne has held a non-executive director role, but yesterday it was confirmed he will no longer be part of the board. Mr Milne has taken the decision to step down with immediate effect.

Prior to entering industry, he was director of the Wolfson Microelectronics Institute, founded in 1968 through a grant from the

Wolfson Foundation, from 1973 to 1984 at Edinburgh University.

Mr Milne was unavailable for comment but it is understood he will retain his shareholding of 2.44% in Wolfson, which is worth more than £6.3m.

Mike Ruettgers, chairman of Wolfson, said: "On behalf of the board, I would like to extend our thanks to David for his outstanding contribution to the development and success of Wolfson over the past 28 years.

"The company has grown from a start-up design house to an international semiconductor company, specialising in the design and supply of high performance audio solutions.

"David successfully led the company in building its solid foundation by establishing Wolfson as a recognised industry leader in mixed-signal audio products and by recruiting highly skilled people.

"During the latter years, Wolfson has continued to develop innovative technology and products for the fast-moving consumer electronics industry and continues to serve an enviable list of brand-leading global customers. The board wishes David well for the future."

Mr Milne, who turns 70 in November this year, received his doctorate in physics from Bristol University and has honorary doctorates from Heriot-Watt and Edinburgh universities.

He was awarded an OBE in 1985 for services to industry and has been a member of the Court of Edinburgh University, a vice president of the Royal Society of Edinburgh and a fellow of the Royal Academy of Engineers. He was director of the Edinburgh International Science Festival and chairman of semiconductor firm Elonics.