The City of London has been knocked out the top five most expensive office locations in Europe after the financial district was overtaken by Paris, Geneva and Dublin following an almost 40% fall in rent over the past year, according to new research.

The City of London, which is heavily reliant on the health of banks and other financial institutions, now sits behind London's West End, Moscow, Le Triangle d'Or in Paris, Geneva and Dublin, according to new figures from property consultant NB Real Estate and Oncor International.