A UK hedge fund manager has raised its stake in retailer J Sainsbury as pressure rises on the Qatari Investment Authority, which last month offered £10.6bn (€15.7bn) for the company, to increase its offer.

Lansdowne, Europe's fifth largest hedge fund manager with $14bn (€10.2bn) of assets under management, increased its holding to 2.3% with the purchase of just under 500,000 shares for 599p on July 30.