China's mainland will become the world's biggest supplier of tourists by 2020, according to a recently released report by CLSA Asia-Pacific Markets.

As many as 115 million Chinese mainland citizens are expected to travel overseas in 2010, higher than the World Tourism Organization's estimate of 100 million, the report said. Outbound travellers from the mainland surged 43 percent in 2004 to 29 million.

Rising personal incomes and the government's easing travel restrictions on individuals will contribute to the increase, according to the report.

In 2004, only 4 percent of China's urban population travelled overseas, leaving huge growth potential, the report said.

As 70 percent of mainland outbound travellers visit Macau or Hong Kong, their holiday spending will bolster stocks of Hong Kong retailers, European luxury goods firms and Macau gaming companies, the report said.

As many as 500 million people are expected to be allowed to travel individually to Hong Kong and Macau next year, up from 200 million this year, the report said.