Luke Johnson, the Channel 4 chairman, has acquired Borders' struggling UK and Ireland book stores in a deal worth £20 million, less than half initial estimates of their value.

Mr Johnson, the former chairman of PizzaExpress, made the acquisition through his Risk Capital Partners private equity vehicle after Borders in the US put the 69 stores, including 28 Books etc sites, up for sale in March.

Initial estimates priced the UK and Irish stores at £50 million. However, Risk Capital Partners is buying the chain for a £10 million upfront payment and an additional £10 million, conditional on the future performance of the business.

Borders in the US will retain a 17 per cent share in the UK and Ireland business but admitted today that it will take a $115 million (£57 million) loss on the shops during its third quarter.

The company is selling the shops to focus on its core US business.

Mr Johnson, worth £120 million according to The Sunday Times Rich List, is well known for floating the PizzaExpress chain with former colleague Hugh Osmond in 1993. His other recent deals have included the £50 million acquisition of six greyhound tracks.

In March, George Jones, the Borders chief executive, told Times Online that the company had decided to retreat from the competitive UK market "because we need to fix our domestic superstores, and that's going to require focus and money".

However, analysts had said that it was hard to see where buying interest for Borders’ UK business would come from.

Like rival Waterstone's, it has suffered amid fierce competition from supermarkets and internet retailers.

HMV bought Ottakar's for £62.8 million last year, having slashed its original £96 million offer for the bookseller after an inquiry into competition issues delayed the deal.

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