SEOUL, March 29 (Xinhua) -- South Korea's central bank and finance ministry on Friday unveiled the detailed volume of their intervention in the foreign exchange market for the first time in a bid to make their foreign exchange policy more transparent.

The FX authorities sold a net 187 million U.S. dollars of foreign currencies in the FX market during the second half of last year to limit a sudden fluctuation in the won/dollar exchange rate, according to the information posted on the Bank of Korea (BOK)'s website.

The net dollar selling put a downward pressure on the won/dollar exchange rate, which stayed at a range of 1,100-1,150 won per dollar in the July-December period.

The U.S. Treasury Department kept South Korea on its "monitoring list" suspecting the country may have intervened in the FX market to devaluate the local currency and help boost exports.

South Korea has denied it, saying that it conducted "smoothing operations" to restrict one-sided market moves.