For all the talk of UK financiers decamping to Switzerland to avoid paying higher personal taxes, London's position as the top financial centre in the world has so far proved unshakeable - the city has topped a list of global economic hubs for the fourth year in a row, according to the latest Global Financial Centres Index.

While Zurich and Geneva retained their 2009 rankings, eighth and ninth place respectively, their ratings fell by four and two points each, according to an index of 75 financial centres compiled by think tank Z/Yen Group.