THE central parity rate of the Chinese currency renminbi, or the yuan, weakened another 160 basis points to 6.7258 against the U.S. dollar Wednesday, according to the China Foreign Exchange Trade System (CFETS).

It was the weakest level since September 2010 and the eighth consecutive day for offshore renminbi depreciation as increased market expectations for an interest rate hike in the United States led to a stronger dollar.

The U.S. central bank will release the minutes of its September monetary policy meeting on Wednesday, which is expected to give out more clues of Fed's further rate-hikes.

In September, the yuan exchange rate composite index, which measures the yuan's strength relative to a basket of currencies including the U.S. dollar, euro and Japanese yen, weakened by 0.28 percent month on month to 94.07, CFETS data showed Monday.

During the same period, the index that measures the yuan against the Bank for International Settlements currency basket weakened by 0.31 percent month on month to 94.75, while that against the Special Drawing Rights basket weakened by 0.06 percent to 95.05, according to the CFETS.

In China's spot foreign exchange market, the yuan is allowed to rise or fall by 2 percent from the central parity rate each trading day.

The central parity rate of the yuan against the U.S. dollar is based on a weighted average of prices offered by market makers before the opening of the interbank market each business day.