South Korea's trade surplus widened from a year earlier last month as its imports shrank at a faster rate than exports, the government said Monday.

The country's trade surplus reached an estimated $3.15 billion in September, compared with a $1.6 billion surplus the same month last year, according to the Ministry of Knowledge Economy.

The figure also marks a growth from $2.04 billion in August.

Exports dropped 1.8 percent on-year to an estimated $45.66 billion with imports shrinking at a faster rate of 6.1 percent from the same period last year to $42.51 billion.

"Though both exports and imports shrank from a year earlier, the rate of the drop for exports slowed significantly and the country's trade balance posted a surplus for the eighth consecutive month," the ministry said in a press release.

Exports in August had dropped 6.2 percent on-year, following an 8.8 percent plunge in the previous month due to what the ministry called seasonal elements.

Exports in September dropped by a narrower margin with shipments of petroleum products, such as gasoline and diesel, surging 24 percent from the same month last year and those of wireless communications devices growing 10 percent on-year.

Outbound shipments of steel products, on the other hand, dropped 9.1 percent while exports of ships more than halved, slipping 50.6 percent on-year, according to the ministry.

The ministry partly attributed the drop in overall exports to a continued global economic slowdown caused by the eurozone debt crisis and also a slower-than-expected growth of major developing countries, such as China.

The country's exports to China only inched up 1.1 percent from a year earlier with shipments to the United States dropping 0.4 percent. Only shipments to the Middle East showed a steady, strong rise, growing 17.8 percent on-year in September. (Yonhap News)