The number of millionaires in the world jumped 9.2 percent to 12 million last year, in part because of simultaneous strength in the stock, bond and real estate markets, according to a study of the high-net-worth population.
The survey, released Tuesday by RBC Wealth Management and Capgemini Financial Services, tracked high-net-worth people, whom it defined as those with more than $1 million that they can invest.
North America was home to the highest number of millionaires - 3.7 million. But the study projected that the Asia-Pacific region, which held the top spot in 2011, would reclaim it.
Part of the strength in North America came from rising equities markets - the Standard & Poor's 500 stock index gained 13 percent in 2012. North American investors put 37 percent of their money into stocks, a higher proportion than people in the Asia-Pacific region, where investors tend to be more conservative, the study said.
The amount of wealth held by the world's richest people also increased substantially, rising 10 percent to $46.2 trillion, well above the pre-economic crisis level of $40.7 trillion in 2007. The study forecast high-net-worth wealth would increase 6.5 percent annually to $55.8 trillion by 2015, mainly because of growth in the Asia-Pacific region.
The survey found that 53 percent of wealthy U.S. individuals would prefer to have a single firm handle their financial accounts. However, a 2011 study from Boston-based research firm Aite Group showed more than half of high-net worth investors held their money in four or more financial institutions.
"Having one super-adviser would be preferred, but finding someone who can do that well is hard," said Aite analyst Sophie Schmitt.
The RBC-Capgemini survey polled more than 4,000 high-net-worth people globally in February and March, including 736 Americans.
(Reporting by Jennifer Hoyt Cummings; Editing by Lisa Von Ahn)