T-Mobile USA will bring in a new top executive to lead its business during a period of uncertainty at the nation's fourth-largest wireless carrier.
Philipp Humm has resigned as CEO, T-Mobile's parent Deutsche Telekom announced.
T-Mobile USA is looking for a new leader. Meantime, T-Mobile USA Chief Operating Officer Jim Alling will temporarily assume the CEO duties.
Humm joined Deutsche Telekom seven years ago and became CEO of T-Mobile USA in November 2010. He has presided over a company that has been struggling with subscriber losses and a failed merger with AT&T.
Deutsche Telekom Chief Executive Rene Obermann complimented Humm on leading some important initiatives.
"Now we need somebody who can convert initiatives into market-successes," he said.