Overseas production by South Korea's leading carmaker Hyundai Motor Co. and its corporate cousin Kia Motors Corp. dropped to a three-year low last month, dragged down by the plunge in output at their plants in China, data showed Thursday.

The combined number of cars produced by the duo at their plants in eight countries abroad reached 289,753 units in July, down 14.1 percent from the 337,278 units tallied a year earlier, according to the data compiled by the Korea Automobile Manufacturers Association.

The figure is the lowest level since July 2012.

Hyundai's July output abroad came to 200,644 units, down 13.9 percent on-year, with the corresponding figure for Kia also down 14.4 percent to 89,109 units over the cited period, the data showed.

The plunge in their overseas production was largely led by their Chinese plants.

Output in such factories nosedived 40.6 percent on-year to 81,466 units. It has been on a downtrend for four consecutive months, with their latest July figure crashing 54.1 percent compared with the month before.

Officials at Hyundai and Kia said the output slump is due largely to their fall in sales in the world's No. 1 auto market amid fierce competition from local carmakers.

"Adverse business conditions have had an impact on production there, with Chinese automakers continuing to grab a larger share of the market with aggressive marketing," a company official said.

According to industry sources, Hyundai and Kia saw their July sales in China plummet 32 percent and 33 percent on-year, respectively. In June, the duo's combined market share in the region came to 7.3 percent, down from the 9.1 percent in the previous month.

The two carmakers under the world's fifth-largest auto giant, Hyundai Motor Group, are also suffering in other major markets because of unfavorable currency rates.

Production in Russia fell 9.1 percent to 12,320 units over the cited period, and that in Brazil also withdrew 11.7 percent to 10,105 units, the data showed.

In contrast, Hyundai's output at its India and U.S. plants grew 4.3 percent and 17.4 percent, respectively, while that of Kia's production facility in Slovakia jumped 28 percent, according to the data. (Yonhap)