Seoul: More than 30,000 customers of KT Corp., the country's second-largest mobile carrier, canceled their subscriptions after the telecom company began waiving contract termination penalties following a major data breach incident, industry sources said Saturday.

According to Yonhap News Agency, 31,634 KT users moved to other carriers between Wednesday and Friday. Of those, 18,720 subscribers, or more than 70 percent, switched to SK Telecom Co., while some 7,200 users moved to LG Uplus Corp.

Industry watchers attributed the strong migration to SK Telecom to the company's subscriber acquisition policies. SK Telecom has been restoring membership benefits for customers who previously left the company following its own hacking incident last year, prompting former users who moved to KT to return.