Chinese Internet giant Tencent has released its popular WeChat application for Research In Motion’s BlackBerry platform, a move that should give it a boost in markets throughout Southeast Asia on its quest for 300 million users.

As noted by 36Kr, Version 1.0 of WeChat for BlackBerry runs on OS 5, 6 and 7. The new app reproduces the core functionality of the service, but it does lacks some of the more advanced features found in the Android and iOS version. Windows Phone and Symbian versions are also available.

WeChat hit 200 million users back in September and is expected pass the 300 million mark next month. The buzz surrounding the service has been quickly growing louder in China and abroad, and it has even had an impact on the popular Sina Weibo microblog.

Though the BlackBerry platform has been in somewhat of a tailspin lately, it is still quite popular in Southeast Asia. Given that the region is a natural next step in the expansion plans for both Line and WeChat, it’s not much of a surprise that they took the time to build a BlackBerry app.

Line arrived on BlackBerry back in August, with developer NHN Japan noting that it was specifically targeted at Indonesia, Singapore and Thailand. The strategy seems to have paid off, as the company announced in December having reached 10 million users in Thailand, a significant feat considering it only has 80 million users around the world.

Of course, BlackBerry’s own messaging platform will feel the competition squeeze as well. Last month, RIM added voice calling to BBM, but the move feels a bit “too little, too late” as voice features have been standard in leading messaging software for some time now.

Even if it will compete with BBM, WeChat’s arrival on BlackBerry OS offers a sliver of hope for RIM. App selection is increasingly becoming one of the most important factors for customers as they choose their smartphone platforms, so having a hit app like WeChat is at least a minor win.

Last week, RIM reported $2.7 billion in revenue and -$0.22 in earnings per share in the third fiscal quarter, which ended December 1. The company lost money, but it wasn’t as bad as Wall Street had originally expected. At this point, all of its hopes are tied up in the upcoming BlackBerry 10 platform, which makes its debut early next year.  However, the bad news for BlackBerry does continue to roll in, as RIM is slated to be removed from the NASDAQ-100 index on Monday.

Image via bryanlyt.com