London and New York will remain the most important world cities for wealthy individuals over the next decade.

This is according to new research from estate agents Knight Frank and Citi Private Bank.

It says Beijing and Shanghai are seen by high-net-worth individuals as the most important up-and-coming cities.

It forecasts that the number of people there worth $100m would grow by 40% by 2016.

According to the wealth report, London ranked top in three of the four categories on which the world's cities were judged in the report - quality of life, knowledge and influence, and economic power.

Washington came top in the category of political power, with London second. Monaco remains the most expensive residential location, with one square metre worth on average $58,300, followed by Cap Ferrat in France, London and Hong Kong.