A record has been set for the world’s most expensive office rents after Permal, a hedge fund group, committed to occupy two floors in the West End – in spite of the woes in financial markets.

The group, an international fund of funds which is part of Legg Mason, agreed on Friday to pay £140 and £130 per sq ft for the fifth and sixth floors of 12 St James’s Square, a redevelopment by D2, a private Irish group.