1st LD-Writethru: Chinese shares tumble Wednesday

China's stocks suffered a heavy blow on Wednesday with the bulk of shares posting declines.

The benchmark Shanghai Composite Index fell more than 4.5 percent in the afternoon session and mildly regained some territory to finish at 2,972.58 points, down 2.31 percent.

The smaller Shenzhen index tumbled 4.13 percent to close at 10,164.74 points.

The ChiNext Index, China's NASDAQ-style board of growth enterprises, plummeted about 6.7 percent before closing at 5.6 percent lower.

Nearly 2,500 shares, or about 89 percent of everything on the two exchanges, posted declines.

The strong performance of banks, insurers and securities brokers contributed to the mild recovery near the close.

Combined turnover on the two bourses expanded by 294.7 billion yuan (45.3 billion U.S. dollars) from Tuesday to 800.6 billion yuan on Wednesday, indicating that many investors dumped holdings to cash in.

In an online survey by news portal Sina.com, more than 1,100 people, or 43.1 percent of respondents, believed that earners' profit taking was the main cause of Wednesday's freefall.

About 47.3 percent of respondents said the stock market is yet to bottom out.

"The slight rebound near the end of the trading may help restore market sentiment, but downward pressure remains considerable," said Wu Zhen, a senior analyst with Jintong Securities. Endi