In local currency terms, the export price index, which gauges export prices with the base year of 2010, retreated to 86.60 in June, down 0.2 percent from a month earlier, according to the Bank of Korea (BOK).
The reading marked the lowest since December 2007 when it recorded 86.45, keeping a downward trend for the fourth consecutive month.
From a year earlier, the export prices dropped 10.6 percent in June.
The falling prices boosted worries about profitability of exporters as lower prices indicate a decline in earnings from overseas.
The South Korean currency averaged 1,019.36 won against the U.S. dollar in June, up 0.5 percent from the prior month.
In contract currency terms, the export prices advanced 0.4 percent in June from a month ago.
Import prices were unchanged in June from a month earlier. Higher global oil prices offset the strong currency effect.
Dubai crude, South Korea’s benchmark, averaged 107.93 dollars a barrel in June, up from 105.62 dollars in May.