The Per Una range has proved popular

M&S had announced plans to acquire the brand when chief executive Stuart Rose unveiled his turnaround strategy for the troubled retailer in July.

Under the terms of the deal, George Davies will stay chief executive of Per Una for at least two years, M&S said.

The Per Una range has been one of the few successes for M&S, which reported another fall in sales last month.

In its most recent trading update, M&S said overall like-for-like sales had slipped 5.2% in the 10 weeks to 18 September, with clothing sales under pressure yet again.

In August, a report by research firm TNS said supermarket chain Asda had overtaken M&S to become the UK's largest clothing retailer.

Reform

George Davies made his name through establishing the Next clothing stores, and then went on to design the George range of clothing for Asda supermarkets.

Per Una was formed as a joint venture between M&S and Mr Davies. George Davies had a supplier relationship with M&S, but following the purchase the retailer will receive all revenues generated by the brand.

The purchase of Per Una was just one of a number of measures unveiled by Mr Rose in July to defeat a potential �9.1bn takeover offer for M&S from retail tycoon Philip Green.

Other reforms included selling M&S's financial services division and closing the Lifestore homeware outlet in Gateshead.