American Investor Warren Buffett is now the richest man in the world, snagging the title from Microsoft chairman Bill Gates, according to Forbes Magazine.

The magazine announced its annual list of the world's billionaires on Wednesday, and for the first time in 13 years, Gates wasn't at the top.

Forbes list of world's richest
Name	Worth ($B US)
1. Warren Buffett	62.0
2. Carlos Slim Helu	60.0
3. Bill Gates	58.0
4. Lakshmi Mittal	45.0
5. Mukesh Ambani	43.0
6. Anil Ambani	42.0
7. Ingvar Kamprad	31.0
8. KP Singh	30.0
9. Oleg Deripaska	28.0
10. Karl Albrecht	27.0
31. David Thomson	18.9

His estimated fortune of $58 billion US, up $2 billion from last year, was eclipsed by his friend Buffett's staggering net worth of $62 billion.

Gates, 52, was also surpassed by Mexican telecom tycoon Carlos Slim Helu and his family, who are worth $60 billion, compared with $49 billion in 2007.

Forbes says Gates's fall to third place was likely due to Microsoft's unsolicited bid for the search engine Yahoo! in early February. Microsoft shares fell 15 per cent between Jan. 31, the day before the bid was announced, and Feb. 11, the day Forbes locked in stock prices to compile its list.

Microsoft, which Gates co-founded 33 years ago, hopes the merger will allow it to better fight Google for internet dominance.

Buffett, 77, was riding the surging prices of holding company Berkshire Hathaway's stock. Class A shares of Berkshire soared 25 per cent between July and Feb. 11. The stock hit a high of $150,000 a share in December.

Buffett, the son of a Nebraska politician who studied under investment guru Benjamin Graham in university, began buying shares in Berkshire in 1962, when it was a textile firm. Buffett purchased a controlling stake three years later.

Today the firm is invested in insurance, jewelry, utilities and food, among other things.

Microsoft chairman Bill Gates, with an estimated fortune of $58 billion, is no longer ranked as the world's richest man.
(Marcus R. Donner/Associated Press)

Buffett, who is heavily invested in insurance firms, has promised to give away his fortune to charity when he dies. He has pledged to direct many of his Berkshire shares to the charitable foundation run by Gates and his wife, Melinda.

The Bill & Melinda Gates Foundation, with $38.7 billion in assets, funds research for AIDS, malaria and tuberculosis vaccines and directs money toward projects helping the world's poor.

Gates is preparing to give up his daily involvement in Microsoft to focus on his philanthropic work with the foundation.

25 Canadians on the list

Twenty-five Canadians made the billionaire list, up from 23 the year before, but the top-ranked Canadian family fell far down the list.

Media mogul and art collector David Thomson and his family have an estimated worth of $18.9 billion US, down from $22 billion US last year. As a result, 50-year-old Thomson plunged to 31st, from 10th, on the Forbes list.

Thomson took control of the family fortune after his father, Kenneth Thomson, died in 2006. At the time, the younger Thomson was already chairman of the family-founded media company, Thomson Corp. The company made a bid in May to acquire Reuters for $17 billion.

Thomson is still the top-ranked Canadian, ahead of grocery magnate Galen Weston and his family (worth $7 billion), and the Irving brothers of New Brunswick's oil and gas industry ($6.7 billion).