Bill Gates is still the world's richest person, and no other technology mogul managed even to crack the top 10.

The Microsoft founder kept his place atop the Forbes list for the 13th consecutive year with an estimated worth of more than $56bn. Second to Gates was US investor Warren Buffett at $52bn.

Gates was the only person in the top 10 whose fortune was made in the tech sector.

Microsoft co-founder Paul Allen slid from five to 19, although the magazine said that Allen's ranking had been over-inflated for several years.

"Our previous net worth estimates failed to account for high levels of debt, or investment losses following the burst of the tech bubble," explained Forbes.

Oracle founder Larry Ellison claimed the number 11 slot with $21.5bn. Google co-founders Sergey Brin and Larry Page shared the number 26 slot with a net worth of $16.6bn each.

The 33 year-old Brin was also the youngest self-made millionare on the list, ahead of Page and Ukranian banker Khostyantin Zhevago.

Also among the top 50 were Michael Dell, with $15bn and Microsoft chief executive Steve Ballmer at $8.8bn.

Google chief executive Eric Schmidt came in at 116 with $6.2bn, and SAP head Hasso Plattner ranked 119 with $6bn.

Apple co-founder Steve Jobs was number 132 with $5.7bn, $4.7bn of which Forbes credits to Jobs's stock holdings in Disney acquired as part of the company's purchase of Pixar.

Only two Brits from the tech industry managed to crack the list. Media mogul Richard Branson came in at 230 with $3.8bn, and mobile phone giant John Caudwell was number 432 with a worth of $2.2bn.