Sprint and T-Mobile confirmed Saturday that they've ended their merger talks , saying they were "unable to find mutually agreeable terms." The Kansas City Star reports that the failure "means shareholders of the two companies gave up $30 billion or more in cost savings that their managements had expected a merger to generate."One combined wireless company would have needed to invest less in its network than the two competing companies spend separately... Absent a merger, Sprint now faces a highly competitive marketplace as the smallest national player and with a more aggressive rival in T-Mobile."Several news outlets had already reported on Monday that Japan's conglomerate SoftBank, which owns Sprint, has pulled the plug on a proposed merger between the two carriers. From a report:Last Monday Sprint and T-Mobile shares both fell immediately following the media reports.