Sprint Corp. and America Online revealed a deal Wednesday to let customers access their AOL instant-messenger service and E-mail from Sprint PCS Vision-enabled mobile phones. The deal makes AOL's IM service available on phones from four out of the five biggest wireless providers.

Sprint PCS mobile phone subscribers who use the provider's PCS Vision data services will be able to access their existing AOL Mail accounts and IM buddy lists and preferences. That will let users engage in real time instant-messaging conversations with co-workers and friends, much as they would on a desktop PC.

When users receive an incoming instant message, they'll get a text message on their phone alerting them and providing a link to log on to AOL's IM. Once there, they can read the message, respond, or access their buddy lists to message other users who are online.

The service improves on Short Message Service, or SMS, communication available on many mobile phones because it provides easy access to all of a user's existing friends and co-workers, Sprint says. "You get the personalization of the buddy list," a spokeswoman says. "It's different from just sending a text message; it's accessing your personal community."

The service could also make it easier for businesses to communicate with mobile workers, says Christopher Foster, a Technology Business Research analyst. Sending or receiving SMS messages to phones requires that you have a compatible phone or log on to the provider's Web site; by using AOL's IM, it'll be possible for someone at a desk to receive a response and reply. But Foster is skeptical that feature will benefit many users. "There's not significant numbers of people using text messaging," he says.

The deal now puts AOL's IM and E-mail onto mobile phones from four out of the five biggest wireless providers, an AOL spokesman says. The only major provider that doesn't participate is Cingular Wireless.

The Sprint service, available now, will only work for users equipped with one of eight Internet-ready PCS phones: the Hitachi P300; the LG 5450; the Sanyo 8100, 5300, and 4900; and the Samsung N400, A500, and A600. Users will incur no charges beyond the normal costs of Sprint's PCS Vision services.