South Korea's monthly current account surplus slipped for a second straight month in January but continued to expand its surplus streak for a 35th straight month, data showed Monday.

The current account surplus hit US$6.94 billion in January, inching lower from a revised $7.02 billion the previous month, according to the preliminary data by the Bank of Korea. The current account is the broadest measure of cross-border trade.

The balance of goods reached $7.09 billion in January, down from an $8.32 billion surplus a month earlier.

Exports dropped 10 percent on-year, while imports slumped 16.9 percent in the same period. Roh Chung-seak, head of the BOK's Balance of Payments team, attributed the fall to a rise in overseas production and a mismatch in the schedule of vessel price calculation.

The service account, which includes outlays by South Koreans on overseas trips, widened its deficit to $2.44 billion from $1.54 billion in December.

The primary income account, which tracks wages of foreign workers and dividend payments overseas, more than doubled to $2.9 billion from $1.21 billion on a rise in dividend income.

Dividend income hit a record $2.32 billion on a monthly basis due to a rise in such income at IT firms that directly invest overseas, according to the central bank.

With the latest result, Asia's fourth-largest economy is poised to renew its record surplus streak of 38 months set since June 1986.

BOK's Roh expected the surplus trend to continue this year in line with a fall in global oil prices. The country's annual current surplus is estimated to reach $90 billion in 2015, according to central bank forecast. (Yonhap)