North American families hold five of the positions among the 10 richest people in the world, with the Walton Family – owner of WalMart – retaining the top spot, according to the Sunday Times (of London) Rich List, published yesterday.

The closely-watched list, which publishes rankings of global and UK wealthy individuals, said that the Waltons had £56.2 billion (around $91.9 billion) of wealth this year, up from last year’s figure of £53.3 billion. In second place is the Mexican telecoms tycoon, Carlos Slim, with £46.2 billion of wealth, followed by IT tycoon and philanthropist, Bill Gates (£35 billion) then the famed investor, Warren Buffett (£31.2 billion).

Taken together, the wealth of the world’s richest 50 people stood at a combined £843.7 billion, a rise of 11.7 per cent on a year before.

There were few dramatic shifts in the rankings of the Rich List this year, at least for the global figures, although the UK list saw some significant shifts in wealth. The largest rise in wealth from 2010 levels was a 164 per cent increase in the assets of Alisher Usmanov, now worth £12.4 billion; the heaviest fall, at -22 per cent, was Lakshmi Mittal and family. (Both Usmanov and Mittal are steelmakers, ironically).

The data further confirms that foreign-born businessmen and women, working in areas such as finance, are a key source of wealth for London, a fact likely to be noted by bankers concerned that the climate of opinion has arguably turned more hostile to wealthy individuals in recent years.

“The presence of overseas billionaires in London and of British tycoons in Switzerland and other low-tax havens is evidence of the extraordinary mobility of money in this age of global markets,” the Rich List commentary said.

The richest Asian family in the UK rankings were Mukesh and Anil Ambani, owners of a large petrochemicals empire (£22.3 billion); the wealthiest European is Johanna Quandt, owner of the BMW automobile manufacturing firm. The wealthiest UK citizen in the global rankings is Lakshmi Mittal, the steelmaker, at £17.5 billion.

Among other details, the Rich List showed that Robert Miller, of the Sail Advisors hedge fund business, is the wealthiest UK hedge fund businessman, with £1.0 billion of assets and ranking 24 in the list of richest Britons. Nat Rothschild, who runs the Attara Hedge Fund business, is equal first, also with £1.0 billion. In second place is Alan Howard, of the Brevan Howard hedge fund business, at £975 million.

The UK’s richest woman is Kirsty Bertarelli, of the pharmaceuticals business, at £6.87 billion, who works closely in the businesses of husband Ernesto Bertarelli (also involved in the America’s Cup of 2010).