Internet portal Naver is set to reap a huge return as its messaging app subsidiary files for an initial public offering that values it at almost $10bn.

Japan-based instant messaging app developer Line has filed for an initial public offering in Japan that would value the company at more than ¥1 trillion ($9.8bn), Reuters reported yesterday.

Launched in 2011, Line offers a mobile messaging service that allows users to exchange text messages and video, along with a free call service. Though it services Japan, Line operates as a subsidiary of Korea-based internet portal Naver.

The company has not disclosed how large a stake it would sell in…