America's technology sector remained a driving force for the world's billionaires, led by Microsoft's Bill Gates and other familiar names, a Forbes survey showed Monday.

Gates, the world's second richest individual on the Forbes list, saw his fortune rise by some $6 billion to $67 billion, but the magazine attributed this to his private equity and other holdings, not to Microsoft.

That allowed Gates to widen his lead among tech billionaires over Oracle founder Larry Ellison, with a net worth of $43 billion -- making him number five overall on the Forbes list.

Amazon's Jeff Bezos, number 19 overall on the list, was third in the tech sector with holdings valued at $25.2 billion. Google's chief executive Larry Page and co-founder Sergei Brin were close behind with $23 billion and $22.8 billion, respectively.

Despite his company's woes, Dell founder Michael Dell held a fortune worth $15.3 billion, making him the sixth wealthiest tech billionaire.

Microsoft CEO Steve Ballmer was not far behind at $15.2 billion, as was a co-founder of the software firm, Paul Allen, with $15 billion, much of that in other holdings including sports teams.

Facebook's Mark Zuckerberg has seen some of the wildest swings in recent years but ranked ninth among tech billionaires with a worth estimated at $13.3 billion.

Zuckerberg's fortune had been pegged at $17.5 billion a year ago, and it could have moved higher after the social network's public offering, but slid to $9.4 billion with the slump in Facebook shares, which have since seen a rebound.

The wealthiest non-American among the tech billionaires was Indian software tycoon Azim Premji, who inherited a cooking oil company and transformed it into India's third-biggest outsourcing services firm, Wipro.

Forbes gave an estimate of $11.2 billion for the net worth of Premji, who last month donated $2.3 billion to an education charity, reportedly the biggest charitable donation in the country's recent history.

Number 11 among the tech billionaires in the Forbes list was the family of Laureen Powell Jobs, widow of Apple co-founder Steve Jobs, with an estimated fortune of $10.7 billion.

Twelfth in the sector was Hasso Plattner, a cofounder of German software firm SAP ($8.9 billion), followed by eBay founder Pierre Omidyar ($8.7 billion), Google chairman Eric Schmidt ($8.2 billion) and James Goodnight of the analytics firm SAS ($7.7 billion).