Subscribers to KT's long-term evolution (LTE) service have surpassed the five million mark, the company said on Wednesday.

Though KT belatedly began offering the service in January 2012, it attracted four million subscribers in just one year -- the fastest in the industry.

And despite 20 days of business suspension in February, it signed up another one million for the service in two months. Earlier this year, all three major mobile carriers were fined and required to suspend business for a certain period of time after they were found to be offering illegal subsidies to draw subscribers.

SK Telecom has the largest number of LTE subscribers with 9.2 million, followed by LG Uplus with 5.2 million.