Non-residents bought a net $2.52 billion in dollar/won NDFs during the April-June period, versus net sales of $11.34 billion in the preceding quarter.

South Korea's won, the best-performer among emerging Asian countries this year, gained 2.7 percent against the dollar during the second quarter, according to the central bank.

Separately, South Korean companies turned net sellers of dollar/won forwards worth $5.0 billion in the second quarter, due to increased hedging by shipbuilders that had enjoyed booming overseas orders.

South Korean companies were net buyers of $1.2 billion of dollar/won forwards in the first quarter.

Copyright Reuters, 2011