SK Telecom Co., South Korea's top wireless carrier, is reviewing measures to share its 3G network with a rival carrier amid declining users on the aging service, a company report showed Thursday.

The carrier said in its annual sustainability report that it is considering measures to share its 3G network with a "competitor" as a way to offset operating costs amid a declining user base.

"Demand for 3G is declining while network operating costs for 3G remain still," its English-language report read. "Discussions are ongoing about the need to develop the 5G industry and increase consumer convenience by terminating 3G services."

The competitor likely refers to KT Corp. as it is the only other local carrier to offer 3G services. LG Uplus Corp., a smaller rival carrier, does not operate a 3G network.

An SK Telecom official said the company has yet to make any decisions over the measure.

As of end-May, South Korea's 3G users stood at just 4.2 million, compared with the total 71 million mobile network subscriptions, according to government data.

SK Telecom's 3G users numbered 1.3 million, far lower than its 7.4 million 5G users and 20.8 million 4G users.

A complete termination of SK Telecom's 3G service will likely be a few years off, as the company only phased out its 2G service last year. (Yonhap)