Seoul: The South Korean won strengthened past the 1,400-won level versus the U.S. dollar Wednesday, marking the strongest level in some 11 months. The won was quoted at 1,397.7 won to the greenback at 3:30 p.m., up 14.1 won from the close of the previous stock trading day. It marked the strongest level since Sept. 24 last year. According to Yonhap News Agency, the won opened at 1,413.3 won per dollar and extended its gains, partly fueled by subdued expectations of a rate hike by the Federal Reserve after better-than-expected U.S. economic data. The Korean currency's advance also came as long-dated U.S. bond yields rose to their highest levels in decades. Moon Jeong-hee, an economist at KB Kookmin Bank, said the won's appreciation appeared to be caused by dollar selling by exporters, while demand for the U.S. currency remained weak. Foreigners sold a net 3.5 trillion won (US$2.45 billion) worth of local stocks during the latest trading session, with the benchmark Korea Composite Stock Price Index plunging 5. 8 percent to close at 6,471.17.