(Adds details on Humm's departure, comments from Vodafone executives.)

--Vodafone hires former T-Mobile USA Chief Philipp Humm to help run its Europe operations

--Humm to run Vodafone's Northern & Central Europe business

--Europe split follows departure of Michel Combes

By Lilly Vitorovich

LONDON--Vodafone Group PLC (VOD.LN), the world's No. 1 mobile operator by revenue, has snapped up T-Mobile USA's former chief Philipp Humm to help run its operations in Europe -- its biggest market by far.

Mr Humm, who resigned from the U.S. wireless carrier 24 hours earlier, will become chief executive of Vodafone's Northern & Central Europe business, overseeing operations in Germany, the U.K., the Netherlands, Turkey, Ireland, Hungary, the Czech Republic and Romania, Vodafone said Thursday.

His departure comes as T-Mobile, part of Deutsche Telekom AG (DTE.XE), struggles to keep pace with larger U.S. rivals and upgrade its network after its $39 billion tie up with AT&T Inc. (T) fell apart due to antitrust concerns.

In a letter to T-Mobile USA staff released Wednesday, Deutsche Telekom Chief Executive Rene Obermann said Mr. Humm informed the company in April that he intended to leave at the end of September so he could return to his family in Europe. But Mr. Humm's exit was brought forward after he informed Mr. Obermann "a few days ago" that he would be joining a competitor of Deutsche Telekom. He didn't name the competitor at the time.

Vodafone said it will split Europe into two new operating regions, Northern & Central Europe and Southern Europe, following the departure of Europe Chief Executive Michel Combes two months ago.

Vodafone's CEO for Italy, Paolo Bertoluzzo, has been given additional responsibility as CEO for the Southern Europe operations, which includes Italy, Spain, Portugal, Greece, Albania and Malta.

Vodafone last month booked a 13% fall in annual net profit to 6.96 billion pounds ($10.82 billion) as dismal economic conditions in Spain, Italy, Greece and Portugal hit customer spending there, prompting a GBP4 billion impairment charge. The U.K.-based operator also warned at the time that conditions in Europe are likely to remain grim for the rest of the year.

Chief Executive Vittorio Colao said both men would be "strong additions" to the executive team.

In Vodafone's press statement, Mr Humm said: "Vodafone is a powerful brand with a strong focus on the customer coupled with a clear strategy for growth," and he said he looks forward to joining the team. He starts in his new role on Oct. 1.

Mr Bertoluzzo said he welcomed "the opportunity to lead such an important part of Vodafone Group's global portfolio through this challenging period." His position is effective from Aug. 1.

Vodafone's decision to appoint two CEOs in Europe suggests that succession to the top job "is not imminent", Sanford C. Bernstein analyst Robin Bienenstock said, noting that the head of Europe has traditionally been the stepping stone to the top job at Vodafone. Combes was also "stretched incredibly thin across loads and loads of countries," she said. Ms Bienenstock has an outperform rating on Vodafone.

At 1322 GMT, Vodafone shares were down 1.1% at 179 pence, valuing the company at GBP88.37 billion ($137.20 billion), in a lower London market.

Write to Lilly Vitorovich at lilly.vitorovich@dowjones.com; Twitter: @LillyVitorovich