ASIANS surpassed Europeans, but fell behind Americans in the self-made billionaires' 2015 list released by UBS and PwC yesterday.

Of the 1,300 surveyed globally, some 36 per cent of the billionaires came from Asia, while those from the United States topped the list at 47 per cent. Europeans were a distant third at 17 per cent.

Entrepreneurship was a strong driving force behind the Asian success stories in the last five years, according to the report co-authored by UBS, the world's largest manager of money for the rich.

The report also found that more billionaires are using philanthropy to establish a legacy.

Anthony Eldridge, PwC's Singapore financial services leader, noted that Asia is expected to be the centre of new billionaire wealth creation in the years to come.

Joseph Poon of UBS Wealth Management noted that as Asian billionaire families grow in size and complexity, succession planning and engaging the second generation have become "increasingly important components in establishing a lasting family legacy".

In the second "Gilded Age" spanning just two decades, more than US$3.6 trillion (S$4.8 trillion) from 917 self-made billionaires has been amassed globally, with most of these billionaires earning their first billion after they turned 40 years old, according to the report.

But amid the exuberance, the report suggests that this period of "extraordinary wealth generation" may soon decelerate.

"While this analysis is historical, our belief is that the conditions in which billionaires thrive are cyclical," the report said.

"The response to rising inequality, increasing taxes and asset price deflation may all play a part in slowing the current cycle."

At the same time, scientific innovations in fields such as biotechnology, artificial intelligence, robotics, nanotechnology and cyber security, as well as the growing needs of an ageing population, suggest that some new opportunities for aspiring billionaires will emerge, the report added.

In the US, the technology sector produced the second-highest number of self-made billionaires in the last two decades.