Barclays’ biggest shareholder, Qatar Holding, sold a 3.5 per cent stake in the bank for a £615m ($1bn) profit on Tuesday, 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 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.