The official, who declined to be named due to the sensitivity of the issue, did not disclose further details such as the timing of the sale and the amounts involved.
The agency held a total of 312.3 trillion won ($240.21 billion) in foreign stocks and bonds at the end of April, according to the agency’s latest data.
The South Korean won has fallen against a much stronger dollar in recent months and broke below the psychologically important 1,300 won per dollar this month for the first time since 2009. ($1 = 1,300.1000 won )