Mexican telecom magnate Carlos Slim Helu topped the Forbes 2013 Billionaires List for the fourth straight year with an estimated fortune of $73 billion, followed by Microsoft Corp. founder Bill Gates with $67 billion, the magazine said Monday.

Amancio Ortega, founder of Spanish fashion brand Zara, overtook U.S. investor Warren Buffett to rank third with $57 billion. Buffett was listed fourth with $53.5 billion.

By country, the magazine found the United States had the largest number of billionaires, at 442, up 17 from 2012. China had 122 on the list, up 27 from last year, while Japan had 22, down by two.

Among the Japanese, Tadashi Yanai, president of Fast Retailing Co., operator of the Uniqlo chain, was listed 66th with $13.3 billion, while Masayoshi Son, president of mobile phone operator Softbank Corp., was 128th with $8.6 billion and Hiroshi Mikitani, president of online retailer Rakuten Inc., 215th with $5.6 billion.

The number of female billionaires shot up by 34 to 138, with France's Liliane Bettencourt, one of the principal shareholders of French cosmetics giant L'Oreal S.A., being the wealthiest among them, ranking ninth overall with $30 billion.

The total number of billionaires has soared in 2013 from the previous year by 200 to a record 1,426, backed by the rising value of shares they hold as part of their assets, the magazine said.

Their aggregate wealth expanded 17 percent to $5.4 trillion, also an all-time high, it added.