BlackBerry devices are set to have Yahoo Messenger software pre-installed, allowing users to chat as well as e-mail on the go.

Full colour, graphical Yahoo Messenger clients will be installed on the devices in "coming months," said BlackBerry's manufacturer Research In Motion Ltd. (RIM). The companies will also offer an enhanced version of Yahoo's Mail service for Blackberrys in the future.

Yahoo already has agreements with a number of mobile operators, including AT&T Wireless Services and T-Mobile USA, to offer Messenger to mobile customers. The Sunnyvale, California, Internet company has tailored versions of its Mail service for mobile phone browsers.

Yahoo is not alone in offering its IM service beyond the desktop, as other leading IM providers Microsoft and America Online (AOL) have also been wheeling and dealing with mobile providers.