The launch of the iPhone5 on Dec. 7 has sparked a war between mobile carriers KT and SK Telecom, over hegemony in Korea’s Long Term Evolution market.

Securing the largest client base is the first priority, the telecommunication firms said, to win a larger share of the smartphone market since the nation introduced LTE.

Although reservations for the iPhone5 began before the official launch, not all applicants stuck to their original orders, a KT official said.

The first-week iPhone sales will provide a better forecast than the reservation statistics of how the LTE market will be divided in the near future, he said.

The first-week sales are significant to all mobile service firms, officials of both KT and SKT said, since the sales of iPhone5 may exert a huge influence over the LTE business rankings.

“About 89 percent of our customers who use the iPhone upgraded to iPhone 5,” a KT official said. “The number means a lot especially when the average rate of upgrading to an advanced model of the same brand is only about 31 percent.”

Meanwhile, many users of the new iPhone shifted back and forth among three telecommunications firms, KT, SKT and LG Uplus, for better deals. LG Uplus did not launch the iPhone5.

According to the Korea Telecommunications Operators Association, SK Telecom attracted about 21,500 clients who had used mobile services provided by KT and LG Uplus on Dec. 7, the first day the iPhone5 went on sale.

About 12,000 SKT clients, at the same time, switched to KT and LG Uplus, the KTOA said.

KT and LG Uplus, on the other hand, lost about 8,400 and 1,200 users, respectively, on the first day.

With the first-week sales still ongoing, more wait-and-see customers are expected to weigh deals offered by the three major mobile carriers.

The Korea Communications Commission warned that it was watching the market for irregularities. The state-run communications watchdog stressed that it would take immediate measures against any reported cases of illegal financial aid or rebates on smartphone sales.

By Chung Joo-won (joowonc@heraldcorp.com)