SHANGHAI, Dec 23 (Reuters) - China stocks ended the week on a bearish note, with the key CSI300 Index hitting a two-month closing low to cap its third straight week of declines, as concerns of tighter regulatory supervision weighed on brokerages and insurers.
The blue-chip CSI300 Index fell 0.8 percent, to 3,307.44 points, the lowest since Oct 17, while the Shanghai Composite Index lost 0.9 percent, to 3,110.00 points.
For the week, the blue-chip index retreated 1.2 percent.
Brokerage and insurance shares fell, amid signs of tougher regulation in the sectors, potentially hurting their revenue streams.
Local media reported that regulators would tighten supervision over online insurance products, as well as brokerages' alternative investment business, the latest efforts to contain financial risks.
Nearly all sectors lost ground at the close, with consumer staple and utilities stocks leading the decline.
Market sentiment was also hurt by a tumble in coal prices, which knocked share prices of coal producers.
Shares of coal majors China Shenhua Energy Co Ltd and Shaanxi Coal Industry Co Ltd were down 1.6 percent and 2.6 percent respectively, as futures contract of coke retreated nearly 4 percent. (Reporting by Jackie Cai and John Ruwitch; Editing by Shri Navaratnam)