MACAO, Oct. 15 (Xinhua) -- The preliminary estimate of the foreign exchange reserves in China's Macao Special Administrative Region (SAR) reached 171.0 billion patacas (about 21.18 billion U.S. dollars) at the end of September, the SAR's Monetary Authority said on Tuesday.

The reserves increased by 0.7 percent from the revised value of 169.8 billion patacas (21.02 billion U.S. dollars) for the previous month. Macao SAR's foreign exchange reserves at the end of September 2019 represented 10 times the currency in circulation, or 81.4 percent of pataca M2 at the end of August 2019.

The trade-weighted effective exchange rate index for the pataca rose 0.59 points month-to-month and 2.78 points year-on-year to 108.3 in September 2019, implying that overall speaking, the exchange rate of pataca increases against the currencies of Macao's major trading partners.