(Yicai Global) Aug. 31 -- The major indices of China's mainboard stock markets closed Thursday's morning session lower. The Shanghai Composite index dropped lower than the 5-day moving average of 3,352.97 points in early trading.
The Shanghai Composite Index was down 0.65 percent to 3,341.83 points, retreating from 3361.46 points at opening.
The other mainboard market index, the Shenzhen Component Index, fell 0.45 percent to 10,765.27 points.
The Growth Enterprise Index closed higher, rising 0.15 percent to 1841.44 points, maintaining its upward trend earlier.
The fall in the Shanghai Composite Index was principally due to the big banks' stocks plunging. The A share of Agricultural Bank of China Ltd. [SHA: 601288; HKG: 1288] was down 2.6 percent. China Construction Bank Corporation [SHA: 601939; HKG: 0939] fell 2.28 percent. Both Industrial and Commercial Bank of China Ltd. (ICBC) [SHA: 601398; HKG: 1398] and Bank of China Ltd. [SHA: 601988; HKG: 3988] were down more than 1.6 percent.