The Q3 tally marks a 27.3 percent fall on-quarter and the lowest since the first quarter of 2010, when the central bank began compiling the relevant data. The figure has been on a constant fall from $8.1 billion in 2013 and $6.2 billion in 2014, the BOK said.

The drop in the overall trade deficit in the third quarter was mainly attributed to a large cut in the deficit from the industrial patents sector, which tumbled to $40 million from the previous quarter's $320 million.

Also responsible was the growth in overseas production by local companies, according to the BOK.

"More companies have set up and run branches overseas, which boosted the country's exports of patent rights while causing a reduction in the country's imports at the same time," said Hwang Sang-pil, an official from the BOK's economics statistics office.

The country's deficit from the industrial design sector fell to $80 million from the second quarter's $140 million, while the trademarks and franchise sector made a turnaround to a surplus of $150 million in the third quarter from the previous quarter's deficit of $260 million.

By industry, the manufacturing sector posted a deficit of $710 million in the third quarter, while the service sector logged a surplus of $300 million.

By country, South Korea posted the largest amount of trade deficit of $1.09 billion with the United States, compared with the previous quarter's $890 million.

The country's largest surplus of $570 million in the intellectual property sector was achieved in trade with China, an increase from the previous quarter's $400 million. (Yonhap)