The sales figure from January to April already reached 72 percent of last year's overall exports of 2,891 PHEVs. The two carmakers exported a total of 1,185 PHEVs in 2015, the data showed.

They have shipped three models of PHEVs -- Hyundai's Ioniq plug-in hybrid and midsize Sonata sedan, and Kia's K5 midsize sedan.

A plug-in electric vehicle es both an internal combtion engine and rechargeable batteries to provide a maximum driving range of over 900 kilometers in the case of the Ioniq PHEV.

The Ioniq plug-in can travel over 900 kilometers with an average fuel economy of 20.5 kmpl, the highest among PHEV cars currently available in South Korea.

Another PHEV based on Kia's Niro plug-in hybrid SUV will be exported as well within this year, a company spokesman said.

In contrast, the automakers' PHEV domestic sales looked weak vis-a-vis export figures.

Hyundai and Kia sold a combined 84 PHEVs here in the first four months. Their PHEV sales climbed slightly to 137 last year from 128 a year earlier, the spokesman said.

"High prices and relatively low government subsidies have limited sales of PHEVs in the domestic market," he said.

The government currently provides about 5 million won ($4,500) per vehicle in subsidies for PHEVs, but it is far lower

than the basic subsidy of 14 million won for an all-electric car. (Yonhap)