The richest person on Earth

And this is so according to the Bloomberg Billionaires Index, a daily ranking of the world s 20 wealthiest individuals. The 72-year-old's net worth fell $478.4 million in a day to $68.5 billion as of the close of markets on March 2, as U.S. moguls Bill Gates and Warren Buffett placed second and third on the list compiled by Bloomberg News.

Slim controls Mexico's America Movil SAB (AMXL).

Brazil s Eike Batista, who ranks 10th, still covets the top spot after vowing a year ago that he d become the world s wealthiest man by 2015. "I m competitive," Batista, who trails Slim by almost $39 billion, said in a March 2 telephone interview from Rio de Janeiro. "It s Brazil s time to be No. 1. Brazilians have always admired the American dream. What s happening in Brazil is the Brazilian dream and I happen to be the example."

The Bloomberg Billionaires Index takes measure of the world s wealthiest people based on market and economic changes and Bloomberg News reporting. Each net worth figure is updated every business day at 5:30 p.m. in New York. The valuations are listed in U.S. dollars.

Today s ranking was published with the release of new billionaires profile pages in the Bloomberg Professional service. The profiles feature a transparent analysis of how each billionaire s fortune was calculated.

Slim's fortune has increased 11 percent this year, according to the index. A spokesman for Slim didn t immediately return a telephone request for comment.

Gates, Buffett Gates, 56, co-founder of Microsoft Corp. (MSFT) in Redmond, Washington, is worth $62.4 billion, down $102.1 million on March 2 and up 11 percent year to date.

The fortune of Buffett, 81, chairman of Omaha, Nebraska- based Berkshire Hathaway Inc. (BRK/B), declined $336.9 million to $43.8 billion on March 2 and is up 2.4 percent in 2012. Almost all of Buffett s wealth is held in Berkshire Hathaway, the publicly traded holding company he has run since 1965.

The combined net worth of the 20 richest people is $676.8 billion. Nine are Americans, including three from the family of Sam Walton, the founder of Wal-Mart Stores Inc. (WMT) Number seven is Larry Ellison, 67, chief executive officer of Redwood City, California-based Oracle Corp. (ORCL), the world s third-largest software maker after Microsoft and SAP AG. (SAP) His $38 billion fortune puts him $4 billion ahead of brothers Charles and David Koch, who each own 42 percent of Koch Industries Inc., one of the biggest closely held companies in the world by revenue. Charles, 76, and David, 71, control the Wichita, Kansas, refiner and chemical maker.

Batista, 55, whose investments range from iron ore to coal, is worth $29.8 billion, up $133.9 million on March 2. His fortune has grown 32 percent this year, the most on the list. The House Wins Sheldon Adelson, the casino magnate who owns 47 percent of Las Vegas Sands Corp. (LVS), which operates resorts in Macau and Las Vegas, is number 13 with $25.7 billion. Adelson, 78, and his family have pledged at least $10 million to a super-PAC supporting Newt Gingrich, a Republican presidential candidate.

Liliane Bettencourt, 89, who with her family owns 31 percent of Paris-based cosmetics company L Oreal SA (OR), is last on the ranking. Bettencourt was the subject of an international scandal in 2007 when her daughter, Francoise Bettencourt Meyers, filed a lawsuit accusing a family friend, photographer Francois- Marie Banier, of exploiting her mother s frail state. Evidence later revealed Bettencourt had granted more than $1 billion in cash and gifts to Banier. In October, Meyers and two grandsons became guardians of the clan s $22.4 billion fortune.

Mark Zuckerberg, the 27-year-old founder of Facebook Inc. (FB), the world s largest social-networking company, didn t make the cut. Based on a roughly $100 billion valuation the Menlo Park, California-based company has been trading at in the private market, Zuckerberg s stake may be worth $21 billion, or about 25 percent less than previous estimates, once Facebook holds its initial public offering.