The Shift will run 2.2 and features a 3.6-in. display, somewhat smaller than that Sprint began selling in June, making it the first 4G on the market.

Verizon Wireless , all with 4.3-in. screens, and Verizon officials pointed out that customers are eager to use larger screens for viewing videos and other content.

But Sprint's David Owens, vice president of consumer acquisition, said Sprint already had the larger screen and felt the smaller Shift display would appeal to more customers not being served by larger screens.

The Shift also has a slide-out horizontal keyboard, something seen in the third of the Sprint 4G phones, including the Samsung Epic 4G, which has a 4-in. screen.

Today's Shift announcement came on the same day as Sprint and Research in Motion announced plans to launch the BlackBerry PlayBook tablet for Sprint's WiMax network this summer.