(Bloomberg News) Carlos Slim, the telecommunications tycoon who controls Mexico's America Movil SAB, is the richest person on Earth, 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. 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. 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., 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.