KakaoTalk, South Korea's No. 1 mobile messenger, became the most frequently visited app in the world in the first quarter, outpacing global rivals like WhatsApp and Facebook, its operator said Friday.

As of end-March, KakaoTalk ranked first in the global top apps list compiled by Silicon Valley-based venture capital firm Kleiner Perkins Caufield & Byers, with the number of sessions per user hitting 55, Daum Kakao Corp. said, quoting the U.S. firm's latest trend report.

The number of sessions refers to how many times a user "opened" or was "engaged with" the app, Daum Kakao said.

WhatsApp, a U.S. smartphone messenger run by Facebook Inc. came in second with 37, followed by China's WeChat, which recorded 29 sessions per user.

Line, a popular mobile messenger in Asia operated by the Japanese subsidiary of South Korea's top portal Naver Corp., was placed fifth with 26 sessions per user, the report showed.

Viber trailed behind as the sixth in the list, with Facebook capturing the seventh spot.

Daum Kakao said the usage session of KakaoTalk turned out to be up to seven times higher than the other five messaging apps on the top 10 list, indicating users' attachment to the mobile platform.

In a separate chart, Facebook was the most widely used app in the world, followed by WhatsApp and Facebook's own Messenger, the report showed. KakaoTalk currently has more than 38 million monthly active users here, in a country with a population of 50 million.

The report was based on collected data from 7,500 Android users in 150 countries during the first three months of 2015. It does not include iPhone users. (Yonhap)