Research In Motion is developing software that will allow its upcoming BlackBerry PlayBook tablet to run Android applications, sources tell Bloomberg.

Citing three unnamed sources, the news service reported that RIM originally tried to use third-party software that would allow its tablet to run Android applications. But after finding nothing suitable, the sources said, RIM decided to work on the solution in-house. The software it's developing will provide access to the Android Market, Bloomberg says.

RIM unveiled its BlackBerry PlayBook last fall. The tablet boasts a 7-inch touch display and runs BlackBerry Tablet OS, a new operating system developed by QNX Software, a company that RIM acquired last year.

RIM itself hasn't made any indication that it will bring Android apps to its platform. At its event unveiling the BlackBerry PlayBook in September, RIM offered details about its own developer program for companies to create programs that run natively on its operating system. The platform supports applications developed in HTML5, Adobe AIR, Flash, Java, and native code.

But that hasn't stopped the rumors from piling up.

Last month, mobile blog Boy Genius Report first reported on the possibility of Android apps coming to the BlackBerry PlayBook. The publication cited sources that said RIM will use the Dalvik virtual machine employed by Android devices to get apps to run on the products.

However, Bloomberg is reporting that RIM opted against using Dalvik over concerns that it could get entangled in patent skirmishes between Google and Oracle.

CNET senior associate editor Nicole Lee pointed out last month when the Boy Genius Report story surfaced that it seems rather unlikely RIM would undermine its own app efforts and offer Android programs on its tablet. And until the company says for sure that this is happening, it's best to consider Android apps running on the upcoming tablet little more than a rumor.

RIM did not immediately respond to a request for comment.