The won was quoted down 0.2 percent at 1,118.3 to the dollar at the conclusion of onshore trade, compared to Tuesday's close of 1,116.0. The weaker finish followed four consecutive days of gains.

South Korean shares were also flat and the Korea Composite Stock Price Index (KOSPI) closed down 0.1 percent at 2,293.08 points.

Foreign investors turned to net buyers of KOSPI shares at the last minute of the trade, purchasing 7.1 billion won ($6.36 million) worth.