That T-Mobile US is even of interest to Sprint and has been poaching customers from larger rivals in recent quarters can in part be credited to Hoettges, who was instrumental in negotiating deals and a turnaround for the unit.
It all began when AT&T's $39 billion bid for T-Mobile in 2011 fell apart because of regulatory opposition. Fortunately, Hoettges and others had insisted on a big break-up fee if the deal with AT&T fell through, which included cash and mobile spectrum worth $6 billion.
The package, especially the spectrum, turned out to be particularly useful to T-Mobile, enabling its launch of superfast mobile broadband services known as 4G. "Tim knew the technology that the team was negotiating for," said a banker.
The banker said T-Mobile was now well positioned in the United States in the event of further consolidation.
"Hoettges created a cookie jar in the U.S. which will provide cash in case of a disposal or a bargaining chip, however the consolidation trend goes," the banker said.
Gervais Pellissier, chief financial officer at Orange, dealt head to head with Hoettges in negotiations to merge their British mobile businesses in 2010.
"He is tough in negotiations but always tries to understand where the other person is coming from," said Pellissier.
During a testy meeting over whether to kill the Orange and T-Mobile brands in Britain, Hoettges sensed that the two sides were at an impasse and suggested everyone take a break for a beer. "I think he knew everything was about to descend into a fight, so he cut it off. He called me a few hours later and we were able to make progress," said Pellissier.
(Read more: Price war over 4G is heating up in Europe)
The future of that venture, now called EE, will be among the strategic decisions Hottges has to take. The owners have said they will consider floating a minority stake in the operator, Britain's largest, valued at about 10 billion euros, though they have pushed back the final decision as EE won 4G customers in recent quarters.
Hoettges will also have to keep a close eye on the German market, which generates about half of group operating profit.
Vodafone, which disputes the top mobile spot with Deutsche Telekom, has bought Kabel Deutschland to boost its broadband offering, while third and fourth-placed mobile groups Telefonica Deutschland and KPN's E-Plus are seeking to merge. Both deals could forceoperators to adopt new commercial strategies to win customers, and mobile prices have already come down in recent quarters.
Hoettges has shown he can play hardball. As head of the German fixed business in 2007 he held out during a month-long strike over a plan to outsource some workers.
Backing down is not something he takes lightly.
One union official said Hoettges reluctantly agreed a deal to raise German wages in 2009 but was never entirely reconciled to the defeat.
"It still irritates him even today. He is very persistent."
Follow us on Twitter: