The Hang Seng Index ended down 2.5 percent at 20,147.3 points. The China Enterprises Index of the top Chinese listings in Hong Kong dived 3.3 percent. For both, this was their worst daily loss since June 20.

Two surveys showing a subdued Chinese non-manufacturing sector discouraged investors. Slowing construction activity was cited for a weak official services PMI reading, while new orders for a similar private survey sank to a 55-month low.

Consumer counters were hit by data showing the value of Hong Kong retail sales grew in May by 12.8 percent from a year earlier, well below April's 20.7 percent growth.