Line Corp. has finally pulled the trigger on an initial public offering after a two-year hiatus. That period of hesitation may have cost the messaging service $4 billion in valuation as Facebook Inc. began encroaching on its turf and markets cooled on technology company debuts.

Japan's leading mobile messaging service is aiming to raise as much as ¥113 billion ($1 billion) in July at a market value of roughly ¥588 billion, according to data in its Friday IPO filings. That's down 40 percent from an estimated ¥1 trillion when it first filed for an offering in 2014.

That may be as good as it gets. Line's gearing up for a battle with far larger rivals like Facebook and China's WeChat as it looks to expand its 218 million user base beyond its strongest markets of Japan, Taiwan and Thailand. The Tokyo-based company, owned by South Korean search portal Naver Corp., plans to use the proceeds to spearhead an expansion across Asia and, eventually, the U.S.