Hong Kong is leading an Asian charge up the ranks of the world's richest people, with at least 20 billionaires living in the territory, an international study shows. The sharp increase in the numbers of super-rich based in the territory - and in Asia in general - is threatening the once unchallenged status of the United States as the home of the world's billionaires. Five of the world's 10 richest people are Asian, including two prominent Hong Kong magnates - Henderson Land Development's Lee Shau-kee, and Hutchison Whampoa and Cheung Kong chief Li Ka-shing. Almost 30 per cent of the world's billionaires are now Asian-based, according to business magazine Forbes' 1996 list of the world's wealthiest people. Two-thirds of Asian billionaires are now based outside of Japan, signalling the rapid growth in Hong Kong, Taiwanese and Asean-based business giants, in particular, over the past five years. Of the world's 447 billionaires - with a combined worth of US$1 trillion - a total of 123 are Asian-based, with 82 of these figures coming from outside of Japan. By comparison, five years ago just 27 billionaires came from Asian countries other than Japan, while 41 came from Japan itself. Hong Kong's total of 20 billionaires puts it in fourth place on a country-by-country breakdown of where the richest people live - behind the US, Germany and Japan. The US has 149 billionaires, ahead of Germany's 52. The contribution of Hong Kong to the list includes Asia's richest man - Henderson's chief Mr Lee, buoyed by a seven-fold jump in his company's shares over the past six years. Mr Lee's fortune is now estimated by Forbes to be at $12.7 billion - making him the world's fourth-richest man, behind only Microsoft head Bill Gates, Berkshire Hathaway chief Warren Buffett and Swiss-based Roche pharmaceuticals patriarch Paul Sacher. Mr Gates heads the rich list with an estimated fortune of $18 billion, up $5.1 billion year-on-year. Next on the list of Asia's mega-rich - and fifth on the overall world list - is Taiwanese businessman Tsai Wan-lin, buoyed by a recent 50 per cent jump in the value of stock in his Cathay Life Insurance. Mr Tsai's fortune is estimated to be in the vicinity of $12.2 billion. Property mogul Mr Li comes in third on the list of Asian businessmen, and sixth on the world stage, at $10.6 billion. The first Japanese businessman to enter the list is property magnate Yoshiaki Tsutsumi - once the world's richest individual, but now rated the world's seventh richest man - whose fortune has fallen prey to falling Japanese property prices. The other member of the Asian quintet now among the world's 10 richest men is Filipino landowner Tan Yu - whose holdings include 6000 acres of land in China worth an estimated $3.6 billion. His total personal fortune is now estimated to be $7 billion. Asia's richest woman is also Hong Kong-based. Nina Wang, the head of the territory's largest privately held property developer, the Chinachem Group, has made the list for the first time with an estimated $3.3 billion. Chinachem owns all or part of 200 buildings in Central, as well as 13 million square feet of floor space in the New Territories. Other Hong Kong businessmen to make the list for the first time include casino operator Henry Fok Ying-tung (with $2.5 billion), property developer Chen Din-hwa ($1.3 billion) and clothing manufacturer KP Chao ($1 billion). The Forbes list purposely excludes royal families and heads of state from consideration on the list, because their wealth results from political heritage rather than economic effort.