South Korea's currency account surplus hit a six-year low in the first half on higher crude oil price, a lackluster shipping industry and the lower number of Chinese travelers to the country, central bank data showed Friday.

Current account surplus was 29.65 billion U.S. dollars in the January-June period, down 16.8 percent from the same period of last year, according to the Bank of Korea (BOK).

It marked the lowest since the first half of 2012 as expensive crude oil increased import costs. Global crude oil price gained 16 U.S. dollars per barrel in the first half from a year earlier, according to the BOK data.

Trade surplus for goods declined to 55.69 billion dollars in the first half from 56.87 billion dollars a year earlier.

Exports, which account for about half of the export-driven economy, increased 8.8 percent over the year to 307.28 billion dollars in the first half, while imports advanced 11.5 percent to 251.59 billion dollars.

Services account logged a deficit of 15.94 billion dollars in the first half, the second-biggest ever recorded by the economy.

The travel deficit registered the second-largest figure of 8.5 billion dollars as the number of Chinese tourists visiting South Korea dropped 3.7 percent in the first half from a year ago.

The transport account recorded the highest deficit of 3.11 billion dollars on oversupply in the global shipping sector and the restructuring among local shipping firms.

The processing service account logged the third-largest deficit of 3.75 billion dollars as domestic chip manufacturers contracted out more processing to overseas foundry subcontractors amid the brisk chip sales.

Primary income account, which gauges dividend, interest income as well as salary, posted the third-highest deficit of 4.78 billion dollars in the first half as dividend payment to foreign investors hit a record high this year.

Financial account, which measures cross-border capital flow without transactions in goods and services, recorded a net inflow of 24.15 billion dollars in the January-June period.

Overseas direct investment by residents was 17.38 billion dollars in the first half, while the foreign direct investment in South Korea was 7.25 billion dollars.

Portfolio investment by local residents into foreign securities was 35 billion dollars, while foreign investment in local stocks and bonds was 17.93 billion dollars.

For the monthly figure, South Korea logged a current account surplus for 76 months through June helped by robust export.

Current account surplus amounted to 7.38 billion U.S. dollars in June, staying in black since March 2012.

Trade surplus for goods reached 10.04 billion dollars as the export kept an upward trend for 20 straight months at 52.25 billion dollars amid strong demand for semiconductors and global trade recovery.

Imports also grew for the 20th consecutive month at 42.22 billion dollars in the month.

Services account logged a deficit of 2.45 billion dollars in June, marking the biggest deficit in four months.

The processing service deficit was 620 million dollars in June, the biggest since February. The travel account deficit was 1.2 billion dollars in June, down from a deficit of 1.34 billion dollars in the previous month.

In June, the number of Chinese travelers to South Korea jumped 49.0 percent compared with the previous month. The figure for Japanese tourists soared 40.2 percent in the month.