HONG KONG (AP) — Swiss bank UBS said Friday that Hong Kong regulators are investigating its work on some initial public offerings on the southern Chinese financial center's stock market.

UBS also said that the city's Securities and Futures Commission notified it this month of plans to take action against the bank and certain unnamed employees over its work as a sponsor of those IPOs.

Possible penalties include paying fines and restitution or a suspension from providing corporate finance advisory services in Hong Kong, the bank said in its latest quarterly earnings statement .

Hong Kong tightened up its stock listing rules three years ago by making the banks responsible for preparing IPO documents and carrying out due diligence liable for misleading information.

In a brief statement, the commission confirmed that an investigation was underway.

"We do not have any further comment to make at this stage," it said.