Further extending its reach from PC to cell phone, Yahoo said a downloadable e-mail client is now available on Sprint devices.

Yahoo Mail for Mobile, which works through a PC-like interface, costs $2.99 per month and can be accessed from six phones, including Vision Multimedia handsets from Sanyo and Treo devices from palmOne. It also allows users to store e-mails.

Subscribers can purchase the service directly from the handset, with charges appearing on their monthly Sprint bill. They can also opt for instant notification of new messages for an additional fee.

"The revenue will be shared between both parties, but the terms of the deal are not being disclosed," Leslie Stafford, a Sprint spokeswoman, told internetnews.com.

Yahoo's Web-based e-mail service competes with Google's Gmail and Microsoft's Hotmail. In recent years, the online players have constantly tried to one-up each other by adding storage, increased security measures and other features.

"Yahoo's products and services have become an essential part of the lives of millions of consumers, and we are focused on extending those services to mobile devices to provide an integrated experience for our loyal consumers whenever, wherever and however they may access the Web," Nicole Leverich, a Yahoo spokeswoman, said.

Yahoo and Sprint signed their first Web content deal in 1999. Since then, Yahoo has put mobile versions of its photo service, instant messaging, search and games on Sprint phones.

Yahoo also works with other carriers, including Verizon Wireless, Nextel and T-Mobile.

For Sprint, the agreement recognizes the importance of mobile data and could prevent customers from switching to Blackberry devices for wireless e-mail.

The wireless channel is increasingly important for Sprint, as traditional wireline phone service becomes more challenging. Added features could raise revenue, as well as differentiate it in a competitive market.