The value of China's currency yuan, or renminbi, Wednesday weakened to 6.6754 to the U.S. dollar from Tuesday's 6.6553, according to data released by the China Foreign Exchange Trading System.

The yuan has picked up strength against the U.S. dollar and seen increased volatility since the People's Bank of China (PBOC), the central bank, announced on June 19 this year to increase exchange rate flexibility.

On Oct. 15, the renminbi hit a new record high of 6.6497 since China abandoned a decade-old peg to the U.S. dollar and allowed its currency to fluctuate against a basket of currencies in 2005.

Based on Wednesday's central parity, the yuan has strengthened against the U.S. dollar by about 2.23 percent from the rate of 6.8275 to the U.S. dollar that was set a day before the PBOC's pledge to increase flexibility.

China will continue with gradual reform of the exchange rate system, Yi Gang, head of the State Administration of Foreign Exchange (SAFE), said at a seminar held by the International Monetary Fund (IMF) in Shanghai Monday.

"The yuan's flexibility has increased since China launched exchange rate reforms in June. We will further boost those reforms, but this must be a gradual process," said Yi, also deputy governor of the PBOC.