Barclays' biggest shareholder, Qatar Holding, sold a 3.5 per cent stake in the bank for a £615m ($1bn) profit yesterday, raising speculation that the investment vehicle of the emirate might raise its holding in UK supermarket group J Sainsbury.

The transaction, worth £1.4bn would give the Qataris the funds to increase their 26 per cent stake in J Sainsbury, people close to the deal said. "It's under analysis," said one banker. Credit Suisse placed 379m Barclays shares, converted from warrants, in the market at 360p apiece, a 6 per cent discount to Monday's closing price. The bank's shares closed down nearly 5 per cent at 363¾p.