London named world's most expensive city

London has been named world's most expensive city, as it surpassed Hong Kong, in a new report.

According to the report by estate agent Savills, the UK capital is twice as pricey as Sydney as and four times more than Rio for companies to place staff, the Guardian reported.

The estate agent Savills said that in London, rising rents and the strong pound had pushed up the typical cost per individual employee of renting somewhere to live and leasing office space to 120,000 dollars a year, putting it well ahead of other global hubs such as New York and Paris which are the only other locations where the combined annual costs of renting residential and office space top 100,000 dollars per employee.

Savills' 12 Cities report is designed to help companies assess the costs of relocating employees. It measures the total cost per employee in US dollars of renting living and working space in some of the world's global hubs.

The calculations are based on the cost of two seven-strong staff teams that are representative of start-up businesses, one based in a "prime financial sector location" and the other in a slightly less prime or creative area, in order to give a representative figure.