A new survey says that Carlos Slim, the Mexican telecommunications tycoon, is the world’s richest person.

The Bloomberg business news agency said Monday that its new list of the world’s 20 richest individuals showed that the 72-year-old Slim is worth more than $68 billion. But it noted that with such wealth, his net worth can fluctuate markedly on any given day, and fell last Friday alone by more than $478 million.

Slim controls Mexico’s America Movil company, one of the world’s leading mobile telecommunications companies. Slim ended atop the list (http://topics.bloomberg.com/bloomberg-billionaires-index/) ahead of two American moguls, Bill Gates, the founder of the Microsoft technology empire, and Warren Buffett, the octogenarian investor who heads the Berkshire Hathaway company. Bloomberg said Gates is worth more than $62 billion and Buffett nearly $44 billion.

The news agency said that both Ingvar Kamprad of Sweden, who controls the Ikea Group furniture retailer, and Bernard Arnault, with a large stake in Paris-based LVMH, the world’s largest luxury goods manufacturer, are worth more than $42 billion each.

The list of richest people includes five from Europe, three from Asia, two from Latin America and one Canadian.