Microsoft co-founder Bill Gates is back on top of the list of the world's richest people, winning back the top spot on the Forbes list from Mexican telecom mogul Carlos Slim Helú.

Forbes' annual ranking of billionaires was released Monday, with Americans dominating the list and comprising 492 of the 1,645 billionaires identified by the business magazine.

Top 10 billionaires Bill Gates, $76B Carlos Slim Helú , $72B Amancio Ortega, $64 Warren Buffett, $58.2B Larry Ellison, $48B Charles/David Koch, $40B (each) Sheldon Adelson, $38B Christy Walton, $36.7B Jim Walton, $34.7B Liliane Bettencourt, $34.5 Source: Forbes.com

The top 10 includes seven Americans including influential investment guru Warren Buffett, conservative brothers Charles and David Koch and two members of the Walton family clan, who control Wal-Mart.

Larry Ellison is CEO of Oracle and Sheldon Adelson is CEO of Las Vegas Sands Corp.

Gates has led the list for 15 of the past 20 years, but in 2010 Mexico’s Slim took the top spot,

This year, Gates’ net worth is estimated at $76 billion by Forbes, compared to $72 billion for Slim.

The third place goes to Spanish clothing magnate Amancio Ortega who owns the Zara retail chain and 10th to Liliane Bettencourt of L'Oreal fame.

Facebook's Mark Zuckerberg rocketed up the list this year to 21st, after he more than doubled his fortune to $28.5 billion as Facebook stock soared.

Other notable newcomers to the list, include Facebook's Sheryl Sandberg and WhatsApp founders Jan Koum and Brian Acton who sold their company to Facebook for $19 billion.