Microsoft Corp. mogul Bill Gates is the world's richest private individual with a $12.9 billion fortune, displacing a Japanese real estate magnate from the top of the annual list of billionaires compiled by Forbes magazine.

Gates's wealth rose from $8.1 billion during the past year as Microsoft's stock price soared, Forbes says in its July 17 issue, released today. Gates was the richest American a year ago, but ranked second worldwide.

Investor Warren E. Buffett rose to the No. 2 spot with $10.7 billion, up from $7.9 billion a year ago. Stock in Buffett's investing company, Berkshire Hathaway Inc., rose 38 percent in the past year.

It was the first time in the nine years that Forbes has been compiling the list that two Americans were at the top.

Japanese real estate magnate Yoshiaki Tsutsumi, who had held the No. 1 spot for the past eight years, fell to a third-place tie -- with Hans Rausing, the Swedish head of packaging company Tetra Laval -- even though the stronger yen caused Tsutsumi's net worth to climb $500 million to $9 billion.

The heirs of the late retailer Sam Walton remained the world's richest family with $23.4 billion, slightly less than a year ago.

Forbes said it excludes from its list royal families and heads of state, because their fortunes come more from political heritage than efforts in the realm of finance.

That excludes the Sultan of Brunei, head of an oil-rich Pacific island nation and often described as the world's richest man. His family's oil, gas and real estate fortune has been estimated at upward of $30 billion.

Microsoft stock has been rising in spite of well-publicized setbacks for the world's largest maker of software for personal computers. In May, the company dropped a $2 billion bid for Intuit Corp. in the face of opposition from the Justice Department, which also is investigating the proposed Microsoft Network on-line service.

As a group, the billionaires club is growing. Forbes counted 388 private individuals or families with at least $1 billion in net worth, up from 358 last year. The group has a total net worth of $893 billion.

Asia was well-represented among the richest. Two of the 10 wealthiest individuals are from Hong Kong, one is from South Korea and one is from Taiwan. Indonesia turned up six more billionaires this year, bringing its total to 10.

"Where there's extraordinary growth, there's extraordinary opportunity," Forbes said.

A year ago, Mexico had 24 billionaires, the most except for the United States, Japan and Germany. But the peso's devaluation late last year cut 14 Mexican billionaires off the list. This year, the United States had 129 billionaire fortunes, followed by Germany with 53; Japan, 37; Hong Kong, 14; Thailand, 12; France, 11; and Indonesia and Mexico with 10 each. CAPTION: FOLLOW THE MONEY The world's 10 richest individuals, according to Forbes magazine, are: 1. Bill Gates

United States $12.9 billion 2. Warren E. Buffett United States $10.7 billion 3. Yoshiaki Tsutsumi Japan

$9.0 billion

Hans Rausing

Sweden

$9.0 billion 5. Paul Sacher

Switzerland

$8.6 billion 6. Tsai Wan-Lin

Taiwan

$8.5 billion 7. Lee Shau Kee

Hong Kong

$6.5 billion

Kenneth Thomson Canada

$6.5 billion 9. Chung Ju-yung

South Korea

$6.2 billion 10. Li Ka-shing

Hong Kong

$5.9 billion