Research In Motion (RIM) has unveiled its first clamshell model, the BlackBerry Pearl Flip 8220, in a bid to reach more buyers with a different form factor from the company's other models.

The new Pearl Flip has support for the features users have come to expect, such as the ability to connect to a BlackBerry Enterprise Server for corporate email access.

However, unlike more recent models, the Pearl Flip does not support 3G mobile networks and does not come with built-in GPS for navigation.

BlackBerry said that the new handset will be available in the US this Autumn, but has yet to announce availability for the UK or other countries.

Weighing in at 111g, the Pearl Flip has a small screen on the outside of its lid as well as the larger 240 x 320 pixel main display. The external screen can be used to preview incoming emails, text messages and phone calls.

"The popularity of BlackBerry smartphones has grown tremendously around the world and the introduction of this exciting new flip phone will help extend the reach of the BlackBerry platform even further," said Mike Lazaridis, RIM president and chief executive.

Like earlier Pearl devices, the new Pearl Flip has a SureType keypad with two letters on each key, rather than a full Qwerty.

This makes it easier to enter text than a standard phone keypad, but heavy email users are likely to prefer the full keyboard of other BlackBerry models. It also features RIM's Pearl mini trackball.

The Pearl Flip is a quad-band handset with Edge capability for faster downloads on GSM networks that support this.

It also supports 802.11b/g Wi-Fi and VoIP calls using UMA, but it depends on individual carriers to enable this feature.

For consumers, a new BlackBerry Media Sync application makes it easy to synchronise iTunes digital music collections with the handset, according to RIM.

For business users, the Pearl Flip has the Documents to Go suite from DataViz, which enables users to edit Word, Excel and PowerPoint documents.

The new handset has Bluetooth for linking with wireless headsets or an external GPS receiver, and a Micro SD slot supporting Flash memory cards up to 16GB.

RIM said that the 900mAh battery provides four hours of talk time and 14 days on standby.