South Korea posted its second biggest monthly export in October, topping 50 billion U.S. dollars for the sixth consecutive month, a government report showed Thursday.

Export, which accounts for about half of the export-driven economy, advanced 22.7 percent over the year to 54.97 billion dollars in October, according to the Ministry of Trade, Industry and Energy.

It was the second largest reading since the data began to be compiled in 1956. The outbound shipment surpassed 50 billion dollars for six months from May.

The export rebounded last month after shrinking 8.2 percent in September when less business days, caused by the Chuseok holiday, the South Korean version of Thanksgiving Day, led to the export reduction.

Excluding the business day effect, the daily export averaged 2.39 billion dollars in October. It was down 4.0 percent from a year earlier, but it marked the third biggest daily export in history.

Import gained 27.9 percent from a year earlier to 48.42 billion dollars in October, sending the trade surplus to 6.55 billion dollars. The trade balance stayed in the black for 81 months in a row.

Most of the country's key export items posted a double-digit growth in outbound shipment last month.

Semiconductor export rose 22.2 percent to 11.59 billion dollars, exceeding 10 billion dollars for the sixth consecutive month on continued demand for chips used for mobile devices.

General machinery shipment soared 51.7 percent to 4.99 billion dollars, posting the highest monthly figure on solid demand from China, the United States and the European Union (EU).

Petrochemical export touched a record monthly high of 4.49 billion dollars in October amid the higher global crude oil price, surpassing 4 billion dollars for 11 months in a row.

Oil product export grew for 24 months through last month, and automobile shipment turned around in two months on the launch of new models.

Steel export rebounded last month on higher global steel price, and computer shipment rose for 19 straight months.

However, display panel shipments reduced 7.9 percent in October, after sliding 12.1 percent in the previous month amid the falling price of liquid crystal display (LCD) panels.

Export for telecommunication devices, such as smartphone, posted a double-digit decline for the third consecutive month as local companies increased production in overseas factories.

Ship export plunged 55 percent in October, continuing to fall by a double-digit for eight straight months amid the shrinking ship orders caused by the weakened global trade.

By country, export to China, South Korea's biggest trading partner, increased 17.7 percent last month. The figure to the United States, the country's second biggest trading partner, surged 47.6 percent.

Those to the EU and the Association of Southeast Asian Nations (ASEAN) advanced 37.1 percent and 19.2 percent, respectively.

For the first 10 months of this year, the export reached a new high of 505.3 billion dollars, up 6.4 percent compared with the same period of last year.

If this trend lasts, the country's export in 2018 was forecast to surpass 600 billion dollars for the first time, the trade ministry said.

The daily export averaged 2.26 billion dollars in October, marking the biggest-ever daily export in history.

In the January-October period, import amounted to 444.1 billion dollars, sending the trade surplus to 61.2 billion dollars.