China Securities Regulatory Commission (CSRC) is investigating CITIC Securities for violating a regulation, the country's largest brokerage firm announced Thursday evening.
"We are notified today that the company is under investigation for allegedly violating the Supervision and Management Regulation for Securities Brokerages," said the company, without referring to any clauses or giving details.
"CITIC Securities will actively assist the investigation and release any progress in a timely manner. The company is operating normally," it said in a statement filed to the Shanghai Stock Exchange, where it is listed.
CITIC Securities' shares dipped one percent Thursday, while all other brokerage firms also posted declines.
The Chinese government has toughened supervision over securities firms since the stock market began to swing in mid-June.
In September, public security authority began to investigate CITIC Securities general manager Cheng Boming and other senior executives for alleged insider trading and information leakage.
