The world now has a record 1,426 billionaires with a combined wealth of $5.4 trillion (£3.6trn), according to a new survey.
The 2013 Forbes annual billionaires issue said a total of 210 new billionaires have been added to the list, with their wealth up $800bn (£530bn) on the previous year.
Mexico’s telecoms entrepreneur Carlos Slim continued to top the list with a net worth of $73bn (£48bn), up $4bn (£2.6bn) in the previous 12 months.
Zara fashion chain boss Amancio Ortega moved up two spots to number three, with a net worth of $57bn (£38bn), to sit behind Microsoft founder Bill Gates.
The surprise shift was for veteran American investor Warren Buffett, who dropped from second to fourth place with $53.5bn (£35.5bn) – even though he increased his wealth by $9.5bn (£6.3bn) in the year.
It was the first time since 2000 that Mr Buffett failed to make the top three in the list.
The 1,426 billionaires have an average wealth of $3.8bn (£2.5bn), up $100m (£66bn) on the 2012 list.
The US continues to lead with 442 billionaires, followed by 386 in the Asia-Pacific region.
There are 366 ultra-rich on the list in Europe, with 129 in the Americas and 103 in the Middle East and Africa.
Forbes said here was a 32% increase in the number of female billionaires, with 138 now on the list.
The richest woman in the world, worth an estimated $30bn (£20bn), is Liliane Bettencourt – whose father foundered cosmetics giant L’Oreal.
Italian fashion head Miuccia Prada ranks 79 on the list with $12.4bn, just slightly behind Facebook founder Mark Zuckerberg’s $13.3bn (£8.8bn) position at 66.
Britain’s richest man, the Duke of Westminster, is listed as the 89th richest person with $11.4bn (£7.6bn).
Sir Richard Branson is ranked 272 on the list with $4.6bn (£3bn) – behind Topshop’s Sir Philip Green at 248 with $5bn (£3.3bn).