When, in May 2007, UK private equity firm 3i Group bought a minority stake in British architects Foster + Partners – one of the firms commissioned to help redesign the transport system of the Muslim holy city of Mecca – the buyout and real estate markets were booming.

Two years later, the property bubble has burst and many new projects have been mothballed. But the investment appears to be holding up well despite the difficult environment. 3i revealed in its latest results that its investment in the business was worth £111m, equivalent to a writedown of about 7.5% based on the reported value of its original investment.