Hong Kong stocks sank on Thursday, while those on the mainland rallied for a third straight day as traders welcomed the replacement of the country's securities regulator over a rout in markets.

The Hang Seng Index fell 1.27 percent, or 203 points, to 15,878.

The Shanghai Composite Index climbed 1.3 percent, or 36 points, to 2,865 on the last day before a week-long Lunar New Year break, and the Shenzhen Composite Index rose 3.2 percent, or 48 points to 1,577. (AFP)