The millionaires in Asia outnumber their counterparts in North America for the first time while the overall financial wealth of high net worth individuals (HNWI) declined across all regions except the Middle East, according to a new study.

The World Wealth Report 2012 released by consultancy Capgemini and RBC Wealth Management has found that the Asia pacific region has 3.37 million high net worth individuals, compared to 3.35 million such people in North America. Asia surpassed Europe in 2010 and in 2011. The number of millionaires in Asia rose by 1.6 percent as it climbed to first position on the list.

Nonetheless, North Americans held the largest share of HNWI wealth at $11.4 trillion, compared to $10.7 trillion in the Asia-Pacific region.

The HNWIs are those with having investable assets of at least $1 million, excluding primary residence, collectibles, consumables and consumer durables. Though the number of millionaires grew 0.8 percent, the global HNWI wealth in 2011 fell by 1.7 percent to $42.0 trillion compared to 9.7 percent growth to $42.7 trillion in 2010.

However, the study says that the investable income of the world's richest has declined due to the turbulent markets.

While more people surpassed the US$1 million disposable income level in 2011, the aggregate wealth of high net worth individuals declined overall, as market volatility took its toll, said George Lewis, Group Head, RBC Wealth Management.

On the list of top 12 countries with largest HNWI population, India was replaced by South Korea for the 12 position and Singapore overtook Hong Kong as home to Asia's wealthy last year. The number of millionaires fell by 17 percent and 18 percent in Hong Kong and India respectively.

The sharp decline of the equity markets and currency value in 2011 lowered the investible wealth of the rich in India. India's high fiscal and current deficit along with the political gridlocks in policy reforms also had contributed to India losing the rank, the report said.

India suffered a slump in its equity market capitalization and its currency in 2011 as a lack of faith in the political process and the slow pace of domestic reforms disappointed investors, the study said, according to a PTI report.

The U.S., Japan and Germany retained their positions as the top three countries with the largest HNWI population.

It is significant that for the first time this year there are now more high net worth individuals in Asia-Pacific than in any other region. However, losses in key markets such as Hong Kong and India meant that wealth contracted in Asia-Pacific overall.

Europe remains third position on the list with 3.17 millionaires worth $10.1 trillion.