The value of yuan weakened slightly as the central parity rate of Renminbi, China's currency, was set at 6.6566 per U.S. dollar Wednesday, compared with Tuesday's 6.6531, according to the data released by the China Foreign Exchange Trading System.

At present, the yuan is allowed to float on the inter-bank foreign exchange market within a daily limit of 0.5 percent each way of the central parity rate.