In the January-July period, exports by Asia's fourth largest economy expanded 6.3 percent, the IIT said. 

It added that with car imports growing at a fast pace, the trade surplus in automobiles has been on the decline since 2014.

The institute under Korea International Trade Association added that the global market share of cars made in South Korea has been declining in recent years from 5.6 percent in 2013 to 4.6 percent in 2016. The country's overall ranking among auto producing nations backtracked from fifth to eighth in the same period.

The think tank said that while car exports to the European Union (EU) shot up 16.3 percent on-year, they contracted 18.3 percent in the U.S., which is one of the largest overseas market for local carmakers such as Hyundai Motor Co. and Kia Motors Corp. 

US market share of South Korean brands, including Hyundai, Kia and Genesis, reached 8.9 percent in 2011 but slid to 7.3 percent in 2017, while figures for China, another major market dropped to 4 percent last year from 7.5 percent in 2014.

For the EU, market share has stayed in the 5 percent range, edging up over the years to 5.7 percent last year from 5.4 percent in 2014.

The report then said for South Korean carmakers to overcome falling exports, they must do more to strengthen their lineup with new models. It added that differentiated marketing strategies may be needed to better respond to changes in overseas demand. (Yonhap)