BlackBerry creator Research in Motion has acquired the developer of the Documents To Go app, DataViz, according to a report by AllThingsD, a technology blog published by the Wall Street Journal.

By picking up DataViz, the BlackBerry manufacturer may be making a move to provide a free version of Documents To Go for BlackBerry users and maintain a hold on its big-business clients. Research In Motion also made another recent acquisition — Cellmania — in a move to expand its app-delivery platform.

DataViz’s Documents to Go is a popular programming for opening and editing Microsoft Word, Excel and PowerPoint files for BlackBerry users. The exact details haven’t been released yet, but the number flying around the Internet is about $50 million. The CrackBerry blog first reported the rumor, stating that several members of DataViz had adjusted their LinkedIn profiles to show new positions at Research in Motion.

DataViz already reportedly canceled development of its Documents To Go for Palm’s WebOS. Whether the document-reading platform will become exclusive to the BlackBerry OS is still unclear.

Research in Motion has been under scrutiny after the lukewarm launch of its BlackBerry Torch, which was billed as an iPhone competitor but had its price cut in half about a week after release. On top of that, Android handset sales overtook BlackBerry sales in August — another possible signal of the shift away from RIM.

We’ll update the story as the details come in.