中国央行宣布人民币贬值1.9%

China's central bank devalued its currency Tuesday in what it said was a one-time move to make rates more market-oriented.

The yuan is allowed to fluctuate 2 percent above or below a central point set daily by the People's Bank of China (PBOC). The PBOC cut the central rate by 1.9 percent as a result of the change that it said would enhance "the market-orientation and benchmark status of central parity."

Beginning Tuesday, the PBOC said the central point would reflect the previous day's closing price "in conjunction with demand and supply condition in the foreign exchange market and exchange rate movement of the major currencies."

A drop in the yuan will make China's exports cheaper overseas. Tuesday's move follows the announcement that July exports were down more than 8 percent from the same time last year.