The daily foreign exchange (FX) trading by banks in South Korea declined 4.7 percent in the third quarter from three months earlier amid the local currency's gain against the US dollar, central bank data showed Wednesday.

The daily FX turnover came to an average $49.56 billion in the July-September period, down $2.46 billion from the second quarter, according to the data by the Bank of Korea (BOK).

The drop came as an inflow of foreign investors' stock funds slowed amid the won's gain and FX derivative transactions declined, the BOK said.

The Korean currency appreciated 2.71 percent to the greenback in the third quarter, compared with three months earlier.

In the third quarter, foreign investors bought a net $2.08 billion worth of South Korean stocks, down from a net $2.82 billion in the second quarter.

The average daily turnover of foreign exchange spots reached $19.72 billion during the cited period, down 2.9 percent from three months earlier, while the daily average FX derivatives fell 5.9 percent on-quarter to $29.83 billion.

By bank, the daily turnover by local lenders dipped 0.8 percent on-quarter to $24.37 billion, while transactions handled by local branches of foreign banks declined 8.3 percent to $25.18 billion, the BOK said. (Yonhap)