Recent setbacks in Japanese stocks set the gloomy tone for the Korean market, which started its first day of trading following the Lunar New Year holiday. Japan's Nikkei 225 plunged over 5 percent Tuesday and 2 percent Wednesday.

On Sunday, North Korea ramped up regional tensions by launching a long-range rocket. Later, South Korea decided to shut down the inter-Korean industrial complex in response to the North's recent nuclear and missile tests.

Most large caps opened sharply lower with market bellwether Samsung Electronics losing nearly 3 percent. Banks, brokerages and other tech issues were among the worst performers.

The local currency was changing hands at 1,191.9 won against the U.S. dollar as of 9:15 a.m., up 5.5 won from the previous trading. (Yonhap)