Shanghai shares ended at a one-month low yesterday after China's insurance regulator signaled strict rules were being planned to curb risky stock investments by insurers.
The Shanghai Composite Index shed 0.46 percent to close at 3,140.53 points.
Insurance companies should act as "friendly investors" in an asset market, and "should by no means become barbarians," said Xiang Junbo, head of the China Insurance Regulatory Commission, on Tuesday.
The speech echoed a warning from Liu Shiyu, the head of the China Securities Regulatory Commission, who last Friday criticized leveraged acquisitions of shares in listed companies by insurance firms.
Infrastructure shares bore the brunt of the selling yesterday.
China State Construction Engineering Corp slumped 5.37 percent to 8.81 yuan ($1.28). Its shares have dived 12.86 percent in three days of trading, tumbling from over 55 percent since October.
China Railway Construction Corp, one of China's two biggest railway builders by revenue, lost 4.98 percent to 11.44 yuan.
