The central parity rate of the Chinese renminbi, or the yuan, weakened 33 basis points to 6.7922 against the U.S. dollar Wednesday, according to China Foreign Exchange Trade System.

Under China's market-based, managed floating exchange rate system, the yuan is allowed to rise or fall by 2 percent against the dollar from the central parity rate in the spot market each trading day.

The central parity rate is a weighted average of quotes from dealer banks and follows a formula based on the previous day's closing rate and changes in a basket of selected currencies.

New figures showed the U.S. manufacturing sector expanded in June and construction spending was flat for the month, which provided some impetus for the dollar.

Investors awaited minutes of the Federal Reserve's June meeting to gauge how committed it was to hiking rates gain this year and any detail on plans to wind back its massive balance sheet, analysts said.

Measured by the central parity rate, the yuan has appreciated more than 2 percent against the greenback so far this year, with more than half of that in the past month.