South Korea's current account surplus declined in April to 4 billion U.S. dollars due to a rise in dividend payment to foreign investors and the continued travel account deficit, central bank data showed Monday.

The current account balance, the biggest measure of cross-border capital flow for goods and services, stayed in black for 62 months to April, but the surplus slumped from 5.75 billion dollars in March, according to the Bank of Korea (BOK). The April figure of 4 billion dollars was the lowest in a year.

For the first four months of this year, the current account surplus reached 23.43 billion dollars, down 19.5 percent compared with the same period of last year.

The BOK said the current account surplus continued to fall amid the higher crude oil prices.

The sharp fall in April was attributable to an increase in dividend payment to foreigners. Primary income account, which gauges investment and interest incomes as well as salary, posted the biggest monthly deficit of 5.03 billion dollars in April.

The previous record-high deficit in the primary income account was 4.06 billion dollars tallied in April last year.

The dividend income account registered the largest monthly deficit of 5.33 billion dollars, accounting for most of the primary income deficit.

The travel account deficit fell from 1.35 billion dollars in March to 1.24 billion dollars in April, but the balance was still in the red as the number of Chinese tourists to South Korea kept sliding.

The services account balance posted the deficit of 2.38 billion dollars, but trade account for goods logged the surplus of 11.93 billion dollars in April, higher than 9.62 billion dollars in March.

The goods trade surplus was the biggest in 10 months. Exports, which account for about half of the economy, jumped 19.2 percent from a year earlier to 48.2 billion dollars in April, while imports advanced 18.6 percent to 36.27 billion dollars.