Probes of securities firms drag down market

Announcements that major Chinese securities firms are under investigation for alleged rule violations triggered a market sell-off on Friday amid investors' concerns about the firms' business prospects.

The benchmark Shanghai Composite Index tumbled by 5.48 percent on Friday, the largest single-day decline since the market rout in August.

Friday's decline, mainly led by the brokerages, came after the country's leading brokerages, CITIC Securities, Guosen Securities and Haitong Securities, said in statements to the Shanghai Stock Exchange late on Thursday and late on Friday that they were under investigation by the China Securities Regulatory Commission.