SK Telecom (SKT), KT and LG Uplus teamed up to launch a Rich Communication Services (RCS)-based messaging service called Chatting Plus, taking aim at the country’s leading messaging app KakaoTalk.

In a joint statement, the three said they completed interoperability testing on their networks with Samsung smartphones. LG Electronics plans to release RCS-compatible handsets later in the year.

The operators are offering free unlimited use of the next-generation messaging service until the end of 2019. Chatting Plus offers messages up to 2,700 characters in Korean and 4,000 characters in English, along with group conversations of up to 100 people and file transfers up to 100MB.

Moon Byeong-yong, head of the messaging service group at SKT, said: “We expect all our customers to experience better messaging services across carrier boundaries.”

In January, the market leader announced plans to introduce a messaging service based on the RCS standard.