世界第一富豪：先知巴菲特

It must count among the world's most genial rivalries. Two of the planet's richest men regularly play epic games of on-line bridge and collaborate over handing out their billions. But Warren Buffett has unseated his friend, Bill Gates, to become the wealthiest individual on the globe.

The Nebraska-based investor known as the Sage of Omaha saw his fortune swell by $10bn (£5bn) to $62bn last year as he made a series of shrewd punts, including a bet on Brazil's currency and profit on the oil company PetroChina, which has drawn flak for its links to Sudan's government.

Buffett's earnings propelled him to the top of Forbes magazine's annual ranking of the world's billionaires, ending a 13-year reign for Gates, who slipped to third with $58bn, behind the Mexican telecoms tycoon Carlos Slim, who has an estimated fortune of $60bn.

Britain's richest resident, Lakshmi Mittal, came in fourth. He is one of 49 billionaires living in Britain, which is renowned among the super-rich for its lenient tax treatment of "non-domiciled" residents.

There is unlikely to be any lavish celebration from the newly anointed richest man in the world. Buffett is known for frugality: for his recent wedding to his longtime partner, he bought a discount ring through his own jewellery company and took his bride to a branch of the Bonefish Grill, an America-wide seafood chain.

"I don't think for a moment it's about being number one for him," said Robert Miles, author of a biography of Buffett. "He's not going to sleep any better or eat any better. It's inconsequential to him."

Buffett's passions include Cherry Coke, hamburgers and homemade candy bars. A Democrat, he says he wants to pay more tax, accusing the Bush administration of lightening the burden on the super-rich.

His wealth has increased despite a series of huge charitable gifts. The 77-year-old pledged in 2006 that he would donate $31bn to the Gates Foundation to help address global healthcare issues. In July he handed over his second annual instalment, $1.76bn worth of shares.

The donation cemented a long friendship with the Microsoft founder. The men sometimes meet to play bridge at a Holiday Inn near Buffett's home. More recently, they have competed online - Buffett uses the soubriquet "tbone" while Gates goes by the screen name "challenger".

"Buffett's still living in the same house he bought when he was 28 for $31,000," said Miles. "He will often kid Bill, who built a $40bn or $50bn mansion, that they ought to bet their houses."

For Gates, times have been relatively tough. The value of his shares in Microsoft has fluctuated on concern that it has failed to stamp its mark on the internet, which Microsoft hopes to change by buying Yahoo. This has allowed Slim, a cigar-chomping owner of Mexico's American Movil telecoms leader, to edge ahead.

Slim, who says he "doesn't really care" about wealth rankings, comes from a country where half the population lives in poverty. But he eschews grand philanthropy. He told an interviewer recently: "Poverty cannot be eradicated through charity."

The Duke of Westminster is the richest Briton, ranking 46th with $14bn. Retail magnate Philip Green comes in 107th with $8.4bn. The Reuben brothers, who built their fortunes on metals but are now in property, are 178th with $5.5bn.

Although only 35 of the world's 1,125 billionaires are British, many more choose to live in the UK. Non-domiciled residents include the Greek easyJet founder Stelios Haji-Ioannou and the owner of Chelsea football club, Roman Abramovich.

Experts say Britain's time zone contributes to its appeal. "These guys are typically not sitting around doing nothing. They're busy, driven global businessmen, and sitting right on top of the GMT time zone makes life easier," said Tony Cohen, head of private client services at the accountancy firm Deloitte.

Britain only taxes domestic assets and income situated domestically, allowing many billionaires to avoid levies in their country of origin - although the government wants to change this. "They can have huge amounts of income and gains elsewhere and pay no tax anywhere," said Cohen, who added that some of his clients would leave if the rules change. "It isn't all about the money - there's something about not feeling wanted."

The youngest billionaire identified by Forbes is Mark Zuckerberg, who set up the social networking website Facebook in his college dormitory room four years ago. Zuckerberg, 23, is worth $1.5bn.

This year's list includes the first billionaires of black African origin. Sudan-born Mo Ibrahim is the founder of mobile phone firm Celtel International. Others are Nigerian sugar merchant Aliko Dangote and South Africa's Patrice Motsepe, a minerals boss.

Rich, richer, richest

1 Warren Buffett Investments $(bn) 62.0

2 Carlos Slim Helu Telecoms 60.0

3 Bill Gates Software 58.0

4 Lakshmi Mittal Steel 45.0

5 Mukesh Ambani Petrochemicals 43.0

6 Anil Ambani Diverse sources 42.0

7 Ingvar Kamprad Ikea stores 31.0

8 KP Singh Property 30.0

9 Oleg Deripaska Aluminium 28.0

10 Karl Albrecht Aldi stores 27.0

11 Li Ka-shing Diverse sources 26.5

12 Sheldon Adelson Casinos/hotels 26.0

13 Bernard Arnault Luxury goods 25.5

14 Lawrence Ellison Software 25.0

15 Roman Abramovich Oil 23.5

16 Theo Albrecht Aldi stores 23.0

17 Liliane Bettencourt L'Oréal 22.9

18 Alexei Mordashov Manufacturing 21.2

19 Alaweed bin Talal Investments 21.0

20 Mikhail Fridman Oil/banking 20.8

21 Vladimir Lisin Steel 20.3

22 Amancio Ortega Zara stores 20.2

23 R, T & W Kwok Property 19.9

24 Mikhail Prokhorov Nickel 19.5

25 Vladimir Potanin Nickel 19.3