"The next real growth area for our business in China is the small-to-medium company sector," said Chi-Won Yoon, co-chairman and co-CEO of UBS in the region, at a forum at the bank's headquarters in Hong Kong.

"We are investing heavily in our business in China to ensure we can serve that sector."

Yoon didn't disclose UBS's current staff count in China, the world's second-largest economy. The headcount could grow to 1,000 to 1,200 in that time period, said a source with knowledge of the expansion plans.

China's capital market has been the growth engine for many Wall Street banks in the region as expansion petered out in other parts of the world.

Yoon said the company's plan is to increase research coverage of small-to-medium companies in China to help with their capital raising needs, including potential stock market listings. UBS plans to increase the research coverage to 350 companies, the source added.

"Once we have that know-how, and we can lead with research, we can build our IB (investment banking) business, so they can advise them go public and the asset management business, so they can handle the funds for them," Yoon added.

Yoon warned that low real interest rates in several Asian economies have the potential to create asset bubbles and it was time for Asia "to wean ourselves off US economic policy."

"Asia's problems across the region are inflation and a threat of bubbles and this requires a tightening of monetary policy, not easing," Yoon added.