Carlos Slim remains the world's richest person for a second year with estimated assets of $74 billion, according to Forbes magazine's annual global ranking of billionaires.
The net worth of Mexico's Slim, 71, whose holdings include the largest mobile phone operator in the Americas, rose $20.5 billion. Bill Gates, 55, chairman of Microsoft Corp., was second again as his net worth rose $3 billion, to $56 billion. Warren Buffett, 80, chief executive of Berkshire Hathaway Inc., held on to third place with $50 billion.
"It wasn't even close this year," said Forbes Media Editor in Chief Steve Forbes. Slim's net worth gained the most of any billionaire compared with 2010, Forbes said.
Mark Zuckerberg, the 26-year-old cofounder and chief executive of social networking website Facebook Inc., jumped to 52nd this year from 212th place last year. There were a record number of billionaires in 2011, with 1,210 total, compared with the previous high of 1,125 in 2008, and there were 214 newcomers in 2011, with 54 from China and 31 from Russia.
Slim's America Movil is the biggest mobile phone company in the Americas, with 225 million wireless subscribers. The company also controls Mexico's largest land-line phone carrier, Telefonos de Mexico, and the largest TV and long-distance operators in Brazil, as well as phone and video carriers in Colombia, Peru and other South American countries.
His holdings in Mexico extend from retail, with the Sanborns department store chain, to banking and construction. He holds stakes in U.S. companies including New York Times Co., Saks Inc. and Bronco Drilling Co.
Of the 1,210 billionaires on this year's list, 648 saw their net worth increase and 160 saw their net worth decrease. Newcomers to the list included Mark Pincus, founder of San Francisco-based Zynga Game Networks Inc., creator of FarmVille.
The $4.5 trillion held by billionaires on the Forbes list represents about 2.3% of the world's wealth. The Credit Suisse Research Institute estimated the world's households had about $195 trillion in assets last year.
No one region dominated the rankings. The U.S. had the largest representation, with 34%, followed by the Asia-Pacific region with 27%.
"This year, the United States is still No. 1 but the lead is shrinking," Forbes said. Ten years ago U.S. residents accounted for about 50% of the list, he said.
Larry Ellison, 66, chief executive of Oracle Corp., rose to fifth this year from sixth in 2010. Ellison's net worth increased $11.5 billion, to $39.5 billion. Redwood City, Calif.-based Oracle is the world's second-largest software maker.
Zuckerberg's net worth made the largest percentage gain of any billionaire, more than tripling to $13.5 billion from $4 billion. Palo Alto-based Facebook was valued at $50 billion in January by Goldman Sachs.
The Facebook magnate was displaced as the youngest billionaire by Facebook cofounder Dustin Moskovitz, who has $1.4 billion. Others on the list with connections to Facebook include Peter Thiel, Sean Parker, Eduardo Saverin and Yuri Milner.