T-Mobile Has a New Side Gig: Fiber Internet

T-Mobile is sneaking into the cable industry’s backyard. The second-biggest cellphone carrier by subscribers has pieced together at least five partnerships with fiber-optic internet providers that could serve millions of customers in the coming years. Those deals, added to the roughly five million homes and businesses already linked to its 5G broadband service over the air, put the company on the cusp of becoming a major home internet provider in its own right. T-Mobile claimed more turf recently when it agreed to pay $4.9 billion for a stake in Midwestern broadband provider Metronet through a joint venture with private-equity giant KKR. The deal followed a $950 million investment with private-equity firm EQT and Lumos. The wireless company has struck at least three other fiber-optic partnerships without disclosing much about their financials or operating metrics. All told, its wired broadband service is marketed in eight states and includes customers around big markets like Denver and New York City. The fiber business is unfamiliar territory for a company with roots in the 1990s wireless boom that never bore the costly job of maintaining a major landline phone system. Investors rewarded T-Mobile over the past decade for remaining a pure-play wireless network with a knack for growing its customer base. The wireless market has since shifted to a more defensive posture. Most Americans already use one of the three top cellphone networks. A richer opportunity awaits companies willing to make the upfront investment to reach tens of millions of U.S. households with fewer options for home-internet service.