Hammerson, will reduce its debts by £386m after selling a 75% stake in a London office development in the UK capital’s biggest property deal this year.

The agreement with Oman Investment Fund, which is backed by the Oman government, marks the end of lengthy negotiations and significantly strengthens Hammerson’s balance sheet.

The FTSE 100 company launched a £584m rights issue in March but analysts feared Hammerson may be forced to go back to shareholders as property values continue to fall.

However, those fears have been lessened by the sale of Bishops Square, home to law firm Allen & Overy.

Daily Telegraph