Phillipp Humm en T-Mobile USA CEO Phillipp Humm resigns <p>Bellevue-based T-Mobile USA says Chief Executive Phillipp Humm is leaving to join his family back in Europe. An analyst says Humm was probably tired of the parent company not investing enough in its U.S. subsidiary.</p><p>Humm was appointed CEO of T-Mobile USA less than two years ago by its parent, Deutsche Telekom. Then, a few months later, AT&amp;T announced that it was buying T-Mobile. That deal ultimately unraveled after the federal government challenged it.</p> Wed, 27 Jun 2012 22:50:20 +0000 Ashley Gross 5421 at T-Mobile USA CEO Phillipp Humm resigns