SK Telecom Co., the nation’s top mobile carrier, said Tuesday it will start selling a new rate plan that offers unlimited calls and text messages and charges only based on the amount of downloaded data, joining the race with two local rivals as mobile trends shift to data-focused services.

The mobile carrier said in a statement that it would start selling the new data-oriented rate plan nationwide Wednesday.

The announcement came after its rivals ― KT and LG Uplus Inc. rolled out similar rate plans early this month.

SK Telecom’s data-based rate plan is similar to its rivals’ versions. The package comes in eight different types of rate plans to choose from, with standard monthly rates ranging from 29,900 won ($27.40) to 99,000 won. Each rate plan will be given a different amount of data available for downloading, according to the company.

The industrywide move to adopt the new rate plan is unprecedented for South Korean mobile carriers, who have depended heavily on profits from subscriptions that include the amount of phone calls made by users.

Market watchers said a rapid growth in mobile data consumption, backed by the widespread smartphone usage, has sparked the need for mobile carriers to revamp their rate offers from a more up-to-date perspective.

The latest statistics by the ICT Ministry showed that the monthly data traffic among 4G users has surged nearly sixfold in the last four years as of end-2014.

South Koreans have been shifting to the Long-Term Evolution network from 3G, as they spend more time on mobile devices watching video streaming instead of making phone calls or sending text messages.

Earlier this month, KT, the nation’s second-largest telecom carrier, launched service plans that charge users based on their data use while offering almost unlimited voice call and messaging services.

This was an unprecedented phone plan in Korea, where Internet-based communications are fast replacing traditional voice calls and text messages.

Under the KT’s new scheme, 300 megabytes per month, is 29,900 won ($27.45) with free mobile calls. Those who pay more than 54,900 won per month can use both mobile and fixed-line calls without restrictions, KT officials said.

Considering KT started offering an unlimited voice call plan for a monthly payment of 100,000 won in 2004, the new plan is almost 70 percent cheaper than 10 years ago, the company said.

So far, telecom companies have designed phone plans based on voice calls and the proportional data service has been offered regardless of different needs among network users.

“This is a paradigm shift,” said Nam Kyu-taek, KT’s marketing chief and senior vice president, during a media conference. “The new scheme will significantly cut telecom service costs for households.”

From news reports