Foreign company mobile handsets' share slipped to a combined 5% in in South Korea's handset market.
According to the data, sales of Apple's iPhone accounted for 3.6% of the South Korean handset market in the April-June period, with devices made by Chinese manufacturers having 1.4%, a Yonhap news report said.
South Korea's three mobile handset makers - Samsung Electronics, LG Electronics, and Pantech - held the remaining share, the data showed.
Apple's share was 8.5% in the fourth quarter of last year on the back of its release of the iPhone 5, but its share slipped to 6.2% in the first quarter.
Apple's second-quarter share in the South Korean handset market is roughly half of the iPhone maker's global market presence of 7.3%, the data showed.
Industry watchers said foreign brands are losing their presence in the local handset market as most handsets sold in the country are high-end, high-priced smartphones.
Foreign handset makers have exited, or are in the process of pulling out from the South Korean market due to sluggish sales, Yonhap said.
BlackBerry, a Canadian smartphone maker, may pull out of South Korea as it has suffered from falling sales in the smartphone market currently dominated by the world's two top smartphone makers, Samsung Electronics and Apple, according to industry sources.
BlackBerry, whose smartphone runs on its own operating system, has undergone sluggish sales in Asian markets.
Motorola Mobility announced in December its plan to close its mobile business in Korea. In July last year, Taiwanese handset maker HTC Corp. also made official its plan to close its Seoul office due to sluggish sales.