BEIJING, Jan. 30  -- Eleven fund management companies were penalized for insider and rat trading, the securities regulator announced Friday.

Five fund management companies, including China AMC and HFT Investment Management Co. Ltd., have been prohibited from handling public fund registration for three to six months, while another six firms were asked to rectify their practice by the China Securities Regulatory Commission (CSRC).

The securities regulator launched a crackdown, focusing on 15 fund management companies, last December.

China's assets management sector saw impressive growth last year, with total business scale topping 10 trillion yuan (1.63 trillion U.S. dollars), up 101 percent year on year.

The CSRC will continue to conduct regular checks to increase risk awareness and guard investors' interests, according to the announcement.