The world's 100,000 "super-rich" last year extended their lead over the merely affluent, an authoritative study of the world's wealthy has found.

Last year, the assets of those with more than $30 million (€22.2 million) to invest - the so-called ultra-high net worth individuals - expanded by 16.8 per cent. By comparison, people with assets of $1 million to $5 million saw their wealth grow by 6.4 per cent.

The number of ultra-high net worth individuals also swelled by more than 10 per cent - more than the growth in the total pool of wealthy individuals.

The number of people with $1 million or more to invest grew by 8 per cent to 9.5 million last year, and the wealth they control expanded to $37,200 billion. About 35 per cent is in the hands of just 95,000 people with assets of more than $30 million.

The study, prepared by Merrill Lynch and Cap Gemini, highlights a growing gap between the super-rich and those who would normally consider themselves wealthy.

The gap has been exacerbated by rising markets and the forces of globalisation, which have allowed a relatively small number of people to accumulate vast fortunes.

Nick Tucker, head of Merrill Lynch's global private client group in the UK and Ireland, said the difference reflected a willingness by the very rich to take greater risks.

"Ultra-high net worth individuals are very aggressive investors," he said. "If things are good, they will do better than the high net worth individuals, who are more cautious."

The study found that wealthy investors dramatically reduced their investments in hedge funds and private equity last year, instead increasing their exposure to real estate and equities.

The developed world continues to dominate the ranks of the world's rich: 64 per cent of high net worth individuals live in the US, Japan, Germany, France or the UK. But in Singapore, India, Indonesia and Russia, the number of high net worth individuals grew by more than 15 per cent last year.

The rise in riches was accompanied by a surge in charitable giving to $285 billion - believed to be a record. Rich individuals donated 7 per cent of their wealth to charity, while the ultra-rich donated more than 10 per cent.

The downside for the super-rich was that the cost of luxury products and activities rose at nearly twice the average rate for goods and services.- ( Financial Times/Guardian service )