South Korea's current account surplus narrowed in December last year from a year earlier due mainly to a sharp rise in the deficit in the service account, central bank data showed Monday.

The country's current account surplus reached $4.09 billion in December, down from a surplus of $6.96 billion a year earlier, according to the preliminary data from the Bank of Korea.

It marked the 70th consecutive month of a current account surplus, which started in March 2012.

The services account deficit widened to $3.77 billion from a deficit of $730 million a year earlier due to a rise in overseas trips and foreign business services.

Also, the goods account surplus slightly narrowed to $8.21 billion in December last year from $8.47 billion a year earlier.

For all of 2017, South Korea's current account surplus fell to $78.46 billion, compared with a surplus of $99.24 billion in 2016, the data showed. (Yonhap)