AT&T launches rollover data plan

(Reuters) - AT&T Inc said it would introduce a rollover data plan for some of its customers, less than a month after smaller rival T-Mobile US Inc launched its own plan. From Jan. 25, 50 million AT&T subscribers under Mobile Share Value plan can move their unused data in a given month to the next one. Unlike T-Mobile's plan, which allows users to keep rolling their data up to a year, any unused rollover data on AT&T's plan will not be transferable beyond one month. (Correct