China's yuan slides in value after Beijing alters currency controls in the wake of weak trade

China's tightly controlled currency, the yuan, has slid by an unusually large margin after Beijing altered its exchange rate policy following a slump in trade.

The central bank said Tuesday's fall was the result of a change aimed at making its exchange rate controls more market-oriented.

The currency fell 1.3 percent against the U.S. dollar from Monday's rate. That was small compared with the daily fluctuations of some other major currencies but the yuan's biggest one-day decline in a decade.

The announcement comes after July exports contracted by an unexpectedly large margin of 8.3 percent from a year earlier, possibly hurt by a strong yuan that makes Chinese goods more expensive in foreign markets.