Three South Korean electric vehicle (EV) battery makers accounted for a third of the global market in the first five months of the year, but their share has slightly slipped since last year in the face of toughening competition with Chinese rivals, a market research firm said Wednesday.

The trio -- LG Energy Solution Ltd., Samsung SDI Co. and SK Innovation Co. -- supplied a combined 88.4 gigawatt-hour (GWh) equivalents of EV batteries in the January-May period, up from 33.6 GWh a year earlier, according to the data by SNE Research.

Their sales of EV batteries sharply rose in line with solid demand for battery-powered vehicles by major automakers, but the combined share edged down 34.9 percent a year ago as Chinese manufacturers expanded their presence on their home turf, the world's top EV market.

LG Energy Solution, which supplies batteries to EV models by Tesla, Volkswagen and Ford, stayed in second place with a 23.1 percent market share in the five-month period, following China's CATL with 31.2 percent.

Two other Korean makers -- Samsung SDI Co. and SK Innovation Co. -- came in fifth and sixth place, respectively, with a razor thin margin.

"The Korean battery trio, which posted a strong performance last year, is losing its share to Chinese manufacturers this year," SNE Research said in a report. "The global competition is expected to intensify as the Chinese market keeps growing and Chinese battery manufactures are expanding their presence in the European market. (Yonhap)