WATERLOO, Ont. -- BlackBerry's messenger service is being updated to allow users to make voice calls over Wi-Fi networks.

Research In Motion (TSX:RIM) says the latest version of its popular BBM service allows users to talk and text at the same time through a split screen feature.

That would allow, for example, a user to send a picture through BlackBerry messenger while talking.

Long distance calls would not incur traditional telephone charges as they would be made over a Wi-Fi Internet connection and not through the phone service provider.

RIM has seen its market share shrink dramatically as competitors Apple and Samsung, among others, released new smartphones amid delay after delay for the Waterloo, Ont.-based BlackBerry maker.

On Monday, RIM announced it plans to unveil its new operating system -- BB10 -- and showcase its new phones on Jan. 30.

Last week, the company gave Canadian politicians and their staff a sneak preview of the yet-to-be-released devices, while it also won U.S. security clearance for the BlackBerry 10 platform.