(Telecompaper) T-Mobile US said it added a net 1.9 million new customers in the fourth quarter of 2017, taking its total base to nearly 72.6 million at year-end. Over the full year, the mobile operator gained more than 5 million new customers for the fourth consecutive year. After meeting its FY guidance, the company said its majority shareholder Deutsche Telekom is considering buying more shares in the US operator.