Mobile number porting cases came close to 640,000 last month, topping 600,000 for a second straight month. Among the three mobile carriers, SK Telecom recorded the largest net subscriber gain.

The Korea Telecommunications Operators Association (KTOA) said on Sunday that last month’s number porting cases totaled 635,361. The figure was slightly lower than the previous month’s 641,932, but remained high.

Number porting topping 600,000 for two months in a row is seen as being influenced by Samsung Electronics’ customer appreciation festival that began in June. Analysts say Samsung Electronics stimulated demand for number porting by running an event that refunded 20 percent of purchase amounts in digital Onnuri gift certificates.

SKT benefited the most last month. It posted a net gain of 3,887 subscribers. LG Uplus added 1,594 customers. KT, however, posted a net loss of 3,586 subscribers. Budget carriers also saw 1,895 customers leave. The move is seen as SKT and LG Uplus absorbing a large portion of customers who left KT in the wake of a personal data leak incident.

The industry expects the number porting market is likely to swing from this month. Activations for Samsung Electronics’ foldable 'Galaxy Z8 series' begin on Aug. 7. A new iPhone launch is also scheduled for September, and competition among carriers to secure subscribers is expected to intensify.