A storm is brewing now that NHN Japan’s Line messaging service has arrived in China, the home turf of Tencent’s rival WeChat app. Recent rumors suggest that China Mobile, the world’s largest carrier, may join forces with Line to go up against WeChat.

Young’s China Business Blog noted the reports, which come from several local media outlets such as SooToo.com. China Mobile has spoken out publicly against Tencent and WeChat, so a partnership with one of its rivals would be a natural next step.

Competition between Tencent and China Mobile would be a clash of titanic proportions. China Mobile sports more than 700 million users, while Tencent boasts 784 million user accounts on its QQ instant messaging service and nearly 300 million on WeChat.

With recent hints that China could open up mobile virtual network operator licenses, Tencent may even be poised to take on China Mobile directly by creating its own telecom service. The company has demurely remained quite on any speculation about the move, but it likely has China Mobile worried.

While WeChat has been the growth story of the year within China, Line has also been tearing up the charts throughout Asia. Recent figures from App Annie showed that NHN has risen to become one of the top publishers on both the App Store and Google Play in terms of monthly downloads. Particularly telling is the fact that NHN jumped past Tencent into eighth place among publishers on the App Store.

NHN is rapidly turning its messaging service into a full-scale entertainment platform. The company’s Line Pop game, which integrates with the messaging service, topped 1 million downloads in just one day and brought in $1 million in revenue in 12 days, according to Distimo. The tactic does appear to be paying off already, as NHN is ranked as the second-highest grossing publisher on Google Play in terms of revenue, behind only Japanese gaming giant GREE.

Line boasts over 80 million users. It’s still a fair distance behind WeChat, but a significant accomplishment nonetheless. A partnership with China Mobile would give Line a sizable boost and level the playing field in its competition against WeChat.

The upcoming messaging war isn’t going to just be waged in China, as WeChat is looking to expand outside of the mainland. The service recently arrived on RIM’s BlackBerry platform, which is popular throughout Southeast Asia. Line has a bit of a head start on WeChat in the broader Asia region, but fortunes rise and fall quickly in this game. With both services lining up the pieces for growth in China and abroad, we’ll definitely have plenty to chat about next year.

(hat tip Sinocism)

Image credit: Daniel Sorabji / AFP / Getty Images