Mr Thompson, who began with just one shop in 1991, said the decision to sell his 50 stores employing more than 800 staff and with an annual turnover of £53 million, was one of the hardest he has had to make.

However, it had been made easier, he said, by the knowledge Scotmid was recognised as an “excellent” company.

He added, “I wanted a deal where I knew there would be no store closures and that all my staff would be well looked after.

Mr Thompson continued, “Many people will of course know I am currently undergoing treatment for prostate cancer and this has been a key factor in my decision to sell the business.

“From a personal viewpoint I will now have additional time to spend on my other interests.

Mr Thompson went on, “Apart from being chairman and owner of Dundee United, I am also chairman of the Scottish Retail Consortium and on the boards of the Scottish Retail Consortium, the British Retail Consortium, the Scottish CBI Council and I also represent Scottish retailers on other matters.”

Scotmid said the purchase of MN&N was a “major expansion leap” which would take its number of stores in Scotland and Northern Ireland to 265 and boost the workforce to over 4600.

The Co-operative company’s chief executive, Colin Bird, said the deal would introduce the Scotmid name to parts of Scotland where it currently did not have a presence.

“From next February we will start a rebranding operation that will see all MN&N stores change to Scotmid,” he said.

“However, customers will still see the same faces behind their counters and will get added value shopping through the Co-operative product.”

The success of MN&N has been something of a coup for Mr Thompson and the relatively small team at the company’s HQ in Broughty Ferry.

At a time when the food-based retail sector has been increasingly dominated by multiples like Tesco and Asda, MN&N has carved a profitable niche for itself in Scotland and become an ever more attractive target for acquisition.

Late last week MN&N announced that a final audit of the financial performance last year had revealed an operating profit (£1.885 million) and a net profit (£1.407 million) higher than had originally been calculated. Turnover for the year for the 50-store chain totalled £52.729 million.

It is known a number of multiples had been courting Mr Thompson and now Scotmid has emerged from the pack as the successful suitor.

Mr Thompson, whose public profile has been heightened since his 2002 takeover of Dundee United, launched MN&N in 1991.

Glasgow-born and an accountant by profession, he came to Dundee 40 years ago to join the then locally-based wholesaler Watson & Philip. He rose through the ranks, joining the board in 1976 and remaining as a director until leaving to launch his own company.

The businessman said the decision to sell had been heavily influenced by his family.

“They have been concerned about my health and have said that as I’ve put so much time and effort into the company it was time to get something back,” he said.

“I am still receiving treatment for prostate cancer and may even have to go away for a time as my treatment continues. I do feel that I now have to take the time to improve my health situation and have bowed to pressure that I should sell Morning Noon & Night.

“Had things been different and my health was not affected I doubt very much if I would have agreed to sell the company.

“It has been very much like a family business. I believe they have treated me more as a friend, but have also understood and respected different roles we have had to play in the business. I would like to

take this opportunity to thank the MN&N staff for their outstanding loyalty over the years and their undoubted contribution in making the company successful.

Away from his involvement with MN&N, Mr Thompson has also served on the Scottish Executive’s six cities review group and the Executive body looking at the possible implications of membership of the Euro on the Scottish economy.

He said, “Part of the deal with Scotmid will be that MN&N will remain as the club’s sponsor for the foreseeable future.”