SHANGHAI, Feb 1 (Reuters) - China and Hong Kong stocks indexes fell on Monday after the release of worse-than-expected China factory activity survey.
China's blue-chip CSI300 index was down 1.5 percent, at 2,901.37 points, by the lunch break, while the Shanghai Composite Index lost 1.8 percent, to 2,688.87 points.
In Hong Kong, the Hang Seng index dropped 0.9 percent, to 19,511.59 points, while the Hong Kong China Enterprises Index lost 1.5 percent, to 8,120.48.
China's official Purchasing Managers' Index (PMI) contracted at its fastest pace in almost three-and-a-half years in January, missing market expectations, and marking the sixth consecutive month of factory activity contraction.
"Economic weakness has always been a major concern for stock investors, so today's PMI data is not unexpected," said Zhou Lin, analyst at Huatai Securities.
"The market has not yet found its bottom as the investor mood remains very gloomy."
A further slide in stocks threatens to trigger an increasing number of margin calls, while an expected regulatory tightening in the bill market also worries investors.
Stocks fell across the board in China, while in Hong Kong, most sectors fell, with the energy shares among the biggest decliners.
(Samuel Shen and Pete Sweeney)