UPDATE 3-T-Mobile US profit beats estimates as it signs up more customers

T-Mobile US Inc first-quarter revenue and profit jumped from a year earlier, beating Wall Street's estimates, as competitive pricing lured new subscribers to its monthly cellphone plans.The company said it added a net 656,000 phone subscribers in the first quarter, up from 617,000 additions a year earlier and substantially more than the 612,000 new subscribers analysts had expected, according to research firm FactSet.T-Mobile, the third-largest U.S. wireless carrier by subscriber count, is await