Lakshmi Mittal, the London-based billionaire whose fortune was forged in the steel industry, is now the world's third-richest man, according to the latest annual rankings published by Forbes Magazine.

Mr Mittal, who is becoming as well known for the conspicuous fashion in which he spends his money as he is for the way he makes it, joined the uppermost ranks of the elite through a series of deals last year. He rose from No 62 on the annual Forbes ranking and is judged to be worth $25bn (£13bn).

He sits behind Microsoft founder Bill Gates, whose fortune stands at $46.5bn, and investment guru Warren Buffett, whose net worth is $44bn. Mr Gates has topped the list since 1994.

The world's appetite for Billy bookcases and flat-pack beds has propelled another newcomer into the top 10. Ikea chief Ingvar Kamprad is ranked No 6, with a $23bn fortune.

There were 24 Britons on the list. Retailer Philip Green and his wife Tina, who own high-street chains Bhs, Topshop and Dorothy Perkins and launched a failed bid to buy Marks & Spencer last year, are the highest ranked. They are at No 68, worth $6.3bn.

Other Britons include the Barclay twins, who built their fortune in real estate and last year bought the Daily and Sunday Telegraph. They are at No 160, worth $3.4bn.

Harry Potter author JK Rowling is worth $1bn, putting her at No 620. Adult entertainment boss Paul Raymond is 488th, worth $1.4bn. Daily Mail press baron Jonathan Harmsworth, the fourth viscount Rothermere, is at 437, worth $1.5bn. Virgin boss Sir Richard Branson is at 170, with $3.2bn. Roman Abramovich, the Russian oil magnate and Chelsea football club owner, is ranked 21st with $13.3bn.

Mr Mittal, 54, who is an Indian citizen, is shy of the media. He spent £57m on a 12-bedroom London home next to Kensington Palace and $60m (£31m) on his daughter's wedding in Paris, which included a performance by Kylie Minogue.

Last year, he bought the US International Steel Group for $4.5bn. At the same time, he merged his US-quoted company Ispat International with his privately owned LNM Group.

New York has the highest number of billionaires, with 34. Moscow and San Francisco tie for second place with 20 apiece. London and Los Angeles each have 18 billionaires.

The list shows that the rich continue to get richer. The ranking identifies 691 billionaires worth $2.2 trillion, up $300bn from the combined worth of the 587 people listed last year.

"This list shows that things are on the move again," said Steve Forbes, the magazine's chief executive.

Other notables on the list include Martha Stewart, who left prison this month after being jailed for five months for lying to federal investigators. The most famous businesswoman in the US appears to be more popular than ever, something reflected in her wealth. She is listed equal 620, with $1bn.

Wealth and worth

1 Bill Gates, Microsoft, $46.5bn (last year: 1)

2 Warren Buffett, Berkshire Hathaway, $44bn (2)

3 Lakshmi Mittal, Mittal Steel, $25bn (62)

4 Carlos Slim Helu, Grupo Carso, $23.8bn (17)

5 Prince Alwaleed, Saudi investor, $23.7bn (4)

6 Ingvar Kamprad, Ikea, $23bn (13)

7 Paul Allen, Microsoft co-founder, $21bn (5)

8 Karl Albrecht, Aldi supermarket, $18.5bn (3)

9 Larry Ellison, Oracle, $18.4bn (12)

10 Robert Walton, Wal-Mart, $18.3bn (6)

Top UK billionaires

68 Philip and Tina Green, Arcadia Group, $6.3bn (last year: 84)

80 Gerald Cavendish Grosvenor, Duke of Westminster, $5.6bn (36)

122 David Sainsbury, J Sainsbury, $4.3bn (116)

151 Bernie Ecclestone, formula one, $3.6bn (136)

160 David and Frederick Barclay, owners of the Daily Telegraph, $3.4bn (159)

170 Richard Branson, Virgin group, $3.2bn (247)

Source: Forbes