A study by Reading University found that city offices are alsonow heavily leveraged and are increasingly owned by private equityvehicles, many with short-term interests. The proportion ofoverseas ownership has more than doubled in less than 10 years,from 20% to 45%, or 36 million sf of office. Multiple owners nowaccount for 54% of the total floor space available in the city. Thedebt outstanding on all commercial property in this country stoodat £138 billion at the end of 2005, more than three times the sizeof the lending peak that preceded the last property crash.

"Traditionally, city property owners took a long-term view ontheir investments and traded infrequently, with almost all officeshaving a single owner," the study stated. "By contrast, much oftoday's investment activity seems focused on short-term gains withless regard for risk. This, in turn, raises a key question: What ifa substantial number of investors exited the market at the samespeed as they entered?"

The sheer weight of money chasing city investments has pushed upthe value of property. Between January 2003 and December 2005, morethan euro 20.4 billion ($26.13 billion) was invested, 45% of whichcame from overseas investors.