South Korea's foreign reserves decreased by nearly 20 billion U.S. dollars in September, the biggest drop in about 14 years.

According to the Bank of Korea on Thursday, the nation's foreign currency reserves totaled 416-point-77 billion dollars as of the end of last month, down 19-point-66 billion dollars from a month earlier.

The sharp on-month decline, the largest since a drop of 27-point-four billion dollars in October 2008, was attributed by the central bank to measures to stabilize the foreign exchange market and a fall in the value of non-dollar assets when converted into the greenback.

As of the end of August, South Korea was the world's eighth-largest holder of foreign exchange reserves, moving up one spot from July despite a a two-point-18 billion dollar decrease in holdings from a month earlier.

China topped the list at over three trillion dollars, followed by Japan, Switzerland, Russia and India.