Asia's population of millionaires outpaced that of North America for the first time last year, but the total net worth of the world's wealthiest people declined in the face of global economic uncertainty.

The newest World Wealth Report says the Asia-Pacific region was home to 3.37 million people having $1 million or more to invest, a 1.6 percent increase from the year before. North America was in second place with 3.35 million millionaires, a drop of just over one percent, while Europe was home to 3.17 million of the wealthiest people.

The annual report found that the world's total number of millionaires remained steady at 11 million people, but their combined net worth dropped 1.7 percent in 2011 to $42 trillion, thanks to the ongoing eurozone sovereign debt crisis and the struggling U.S. economy.

North America remained the world's richest region with $11.4 trillion in assets, compared to $10.7 trillion in Asia-Pacific and $10.1 trillion for Europe. The Middle East was the only region where millionaires increased their net worth, posting a 0.7 percent boost to $1.7 trillion.

The number of people with assets of $30 million or more to invest saw their ranks decline by 2.5 percent to 100,000 people, while their combined fortunes shrank about 5 percent.