MACAO, April 15 (Xinhua) -- The preliminary estimate of the foreign exchange reserves in China's Macao Special Administrative Region (SAR) reached 163.3 billion patacas (about 20.19 billion U.S. dollars) at the end of March, the SAR's Monetary Authority said on Monday.

The reserves decreased by 2.1 percent from the revised value of 166.8 billion patacas (about 20.63 billion U.S. dollars) for the previous month. Macao SAR's foreign exchange reserves at the end of March represented 10 times the currency in circulation, or 79.8 percent of pataca M2 at the end of February this year.

The trade-weighted effective exchange rate index for the pataca dropped 0.03 points month-to-month but rose 5.07 points year-on-year to 105.6 in March, implying that overall speaking, the exchange rate of the pataca declined against the currencies of Macao's major trading partners on a monthly basis but increased on an annual basis.