BlackBerry wireless e-mail devices will soon come with Yahoo's Messenger software installed, allowing users to chat as well as send and receive e-mail on the go.
Full color, graphical Yahoo Messenger clients will be installed on the devices in "coming months," BlackBerry maker Research In Motion says.
RIM and Yahoo will also offer an enhanced version of Yahoo's Mail service for Blackberrys in the future, they say.
The alliance allows Yahoo to get its instant messaging software onto yet another platform, while RIM gains another feature to offer to BlackBerry customers.
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 have also been wheeling and dealing with mobile providers.