Key TakeawaysT-Mobile announced an agreement Tuesday to acquire most of U.S. Cellular's wireless operations for about 4.4billion.ThedealwouldgiveT−MobilealargerfootprintamongmoreruralareasoftheU.S.U.S.Cellularsharesjumpedsoonaftertheopeningbell.TelecommunicationsgiantT−Mobile(TMUS)announcedTuesdaythatitwouldacquire"substantiallyall"ofU.S.Cellular′s(USM)wirelessoperationsinadealvaluedat4.4 billion. U.S. Cellular customers would receive access to T-Mobile's exp ...