BEIJING, June 8 (Xinhua) -- China's currency, the yuan, dropped Friday for the second consecutive day against the U.S. dollar after it challenged the 7.64 barrier for the first time on Wednesday, according to the China Foreign Exchange Trading System.

The central parity rate of the yuan, also known as Renminbi (RMB), stood at 7.6656 yuan to one U.S. dollar on Friday, down 154 basis points from the previous trading day, or 258 basis points from Wednesday's record high of 7.6398 yuan to one dollar.

The yuan has climbed 1,585 basis points from 7.8087 yuan to one U.S. dollar posted on the last trading day of 2006, and the value of the yuan increased by 0.72 percent in May, the record for a single month since July 2005 when the country discontinued yuan's peg to the dollar.

The People's Bank of China, or the central bank, widened the floating band of yuan against the dollar for daily spot trading on the inter-bank market from 0.3 percent to 0.5 percent from May 21.

On Friday, the yuan gained 390 basis points over the Thursday level to reach a central parity rate of 10.2895 yuan against the euro.