Research In Motion (RIM) diversified its BlackBerry line Wednesday by introducing a "flip" or clamshell model, a popular form for mobile phones.

The BlackBerry Pearl Flip 8220 will be available later this year through operator T-Mobile, although RIM didn't say at what price.

The Pearl Flip represents another move by RIM to widen its prospective customer pool beyond business users, with smaller and more stylish models aimed at consumers yet still retaining the core BlackBerry features.

It has an external LCD (liquid-crystal display) used to preview e-mails, text messages and phone calls. When flipped open, the phone reveals a larger screen and a Qwerty keyboard, one of the characteristic features of RIM's larger devices.

The quad-band phone will operate on GSM networks in the Americas, Europe and Asia, and can connect to EDGE (Enhanced Data Rates for GSM Evolution) data networks, RIM said.

The Pearl Flip ships with stereo headphones and, like other recent BlackBerry models, includes media player software for videos and music. It stores tunes on removable MicroSD memory cards, and will work with cards up to 16G bytes in capacity when they become available. Music tracks without DRM (digital rights management) can be synchronised with Apple's iTunes music jukebox software through a new software add-on, RIM said.

The phone's integrated 2 megapixel camera with flash can shoot still pictures and also record video.

The device is loaded with the DataViz Documents to Go software suite, which lets users edit Microsoft Word, Excel and PowerPoint documents. It has a Bluetooth short-range wireless interface for connecting to headsets and GPS receivers, and Wi-Fi 802.11b/g.