Chinese stocks posted their biggest daily gain in two weeks Wednesday following market rumor about strong export growth in May, which eased market concerns over weakening economic growth.

The Shanghai Composite Index closed at 2,583.87 points, up 69.92 points, or 2.78 percent from the previous close.

The Shenzhen Component Index ended at 10,346.27 points, up 307.49 points, or 3.06 percent, from the previous close.

Total turnover expanded to 196.07 billion yuan (28.71 billion U.S. dollars) from 142.39 billion yuan on the previous trading day.

Gainers outnumbered losers by 869 to 22 in Shanghai and 868 to 93 in Shenzhen.

Market excitement about positive export data spread on Wednesday ahead of the official release. China's export growth is rumored to have surged in May about 50 percent year on year -- higher than market expectations.

The official export data is scheduled to be released Thursday.

Bank shares led the rise by surging 6.02 percent, driven by the rumor that China Central Huijin Investment Ltd., an investment arm of the government, would increase its stake in the banking sector.

China CITIC Bank and Bank of Ningbo rose by the daily limit of 10 percent to 5.51 yuan and 11.47 yuan, respectively. Bank of China, China's third-largest lender, went up 3.42 percent to 3.63 yuan per share.

China's securities regulators Wednesday began reviewing the initial public offering application of Agricultural Bank of China Limited (ABC), the country's main rural lender.

According to the preliminary prospectus submitted to the CSRC, the ABC plans to sell up to 22.24 billion A-shares on the Shanghai Stock Exchange and up to 25.41 billion shares in Hong Kong, excluding an over-allotment option.

The bank is yet to decide its share price range.

Analysts believe that the bank's IPO would bring further fluctuations to the A-share market, which is still tracking downward.

But according to Li Kaifa, economist with Chinese Academy of Management Sciences, said the IPO could also help stablize the market by attracting more capital outside the market.