South Korea's current account surplus narrowed in April from the previous month on smaller trade gains and an increase in foreign investors' dividend repatriation, the central bank said Wednesday.

The current account surplus reached US$3.97 billion in April, compared with a revised surplus of $4.93 billion the previous month, according to the Bank of Korea (BOK). The current account is the broadest measure of cross-border trade.

The April reading marked the 15th straight month of a surplus run and the cumulative surplus amounted to $13.94 billion in the first four months of this year.

The data came as the yen's slide is feared to crimp Seoul's exports as it puts Korean exporters at a disadvantage in pricing in overseas markets. The local currency has risen more than 20 percent against the yen since November.

BOK Gov. Kim Choong-soo has said that the yen's weakening trend is likely to persist for a long time, noting that its negative impacts on Korea's exports will become visible down the road.

In April, Korea's goods balance posted a surplus of $3.59 billion, down from a revised $4.16 billion surplus in March.

Last month, exports rose 3.8 percent on-year to $47.56 billion while imports inched down 0.2 percent to $43.97 billion.

On a customs-cleared basis, Seoul's overseas shipments edged up 0.4 percent on-year to $46.27 billion with its exports to Japan declining 11.3 percent.

The primary income account, which tracks wages for foreign workers and dividend payments overseas, logged a shortfall of $1.09 billion in April, compared with a deficit of $222.3 million in March.

In March and April, offshore investors usually repatriate dividend payments by Korean companies that close their books in December.

The service account, which includes outlays by South Koreans on overseas trips, posted a surplus of $1.45 billion last month, compared with a surplus of $905.1 million the previous month.

Meanwhile, the capital and financial account, covering cross-border investments, posted a net outflow of $2.57 billion last month, compared with a net outflow of $6.79 billion in March, the central bank said.

In April, the BOK slightly revised up the 2013 current account surplus estimate to $33 billion from $32 billion. Last year, Korea's current account surplus reached a record high of $43.14 billion. (Yonhap News)