GeekWire reported that a leaked internal memo reveals Humm is leaving to work for a competitor. CNET's messages to Deutsche Telekom, the company that owns T-Mobile, have not been returned, but ZDNET reported a confirmation from Deutsche Telekom that Humm will indeed be joining a rival company.
Deutsche Telekom's Rene Obermann penned the memo, indicating that he has already spoken to a number of candidates. According to the company's press release, T-Mobile COO Jim Alling will take over Humm's duties as the company searches for a new CEO. The release said Humm was going to pursue a career outside the company.
"Philipp Humm has given the company some important initiatives over the past years: Under his leadership the cost situation at T-Mobile USA has vastly improved and he led the company during a difficult phase regarding the planned merger with AT&T," Obermann said in the release. "Now we need somebody who can convert initiatives into market successes."
Prior to heading T-Mobile USA, Humm was Deutsche Telekom's European regional chief. He led the company's five national mobile companies in Austria, the Czech Republic, the Netherlands, the U.K., and Poland, and played a key role in a U.K. joint venture between T-Mobile UK and Orange UK of France Telekom.
Update, 11:21 a.m. PT: Adds confirmation from ZDNet.