Sprint unlimited plans get 'guaranteed' for leg up on Verizon, AT&T

Sprint is introducing a new wireless plan that guarantees new and existing subscribers unlimited voice, text and data plans, in a move to differentiate its service from rivals AT&T and Verizon.

Sprint Nextel Corp. said Thursday that the plan, called the "Sprint Unlimited Guarantee," offers unlimited data for $30 a month on smartphones and $10 per month on traditional phones. Voice and text cost $50 for the first line and less for additional phone lines.

Sprint, the third-largest U.S. wireless carrier, is now under the control of Japanese investment firm SoftBank. Softbank owns a 78 percent stake in Sprint after a $21.6 billion deal closed on Wednesday.

Both AT&T Inc. and Verizon Wireless have ditched unlimited data offerings to new customers. Late last year, the companies introduced shared-data plans that allow all of a family's devices to share a pool of monthly data usage.

Sprint CEO Dan Hesse said there has been a lot of chatter about when the company would "follow the crowd" and stop offering unlimited plans the way AT&T and Verizon have. The guarantee, he added, is a way of telling customers that "we are not going to pull the rug out from under you."

"We are distinctly different in our market position (from) AT&T and Verizon," Hesse said in an interview.

The "guarantee" in the unlimited guarantee only applies to the "unlimited" part, not the price. And while Hesse said Sprint has no plans to stop offering unlimited plans to new customers, it certainly can in the future, even if that's years from now.

Both AT&T and Verizon "grandfathered in" the unlimited data plans to existing customers before getting rid of them for new ones. But Verizon charges customers the full price of a phone if they want to upgrade to a new model and keep their unlimited plans.