BEIJING - The Chinese mainland has 157 billionaires as of 2013, ranking second in the number of billionaires worldwide, a banker said Tuesday.

"It follows the United States, which has 515 billionaires," Jin Jixiang, president of UBS (China) Limited, said at a press conference.

He said billionaires from the mainland have an average age of 53, which is nine years younger than the global average, adding that Hong Kong ranks seventh, with 75 billionaires in total.

Jin made the remarks when introducing the Wealth-X and UBS Billionaire Census, a report released earlier this month by UBS and Wealth-X, a Singapore-based investigative institute.

The report said the number of billionaires worldwide in 2013 has risen to the highest, standing at 2,170, an increase of 60 percent on the 2009 figure.

Despite the global financial crisis, billionaires have become richer as their total combined wealth rose to $6.5 trillion in 2013, up from 3.1 trillion dollars in 2009, the report said.

The report also forecast that the global billionaire population will increase by 1,700 individuals by 2020 to nearly 3,900.

By region, the population of billionaires in Asia has grown 12.9 percent from 2012. At current growth rates, Asia is set to have more billionaires than North America by 2018. Europe is the only region with fewer billionaires than 2012, down 3.6 percent, the report said.