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 apace 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.

Nearly two months after Vodafone lost its Europe chief executive, Michel Combes, to French telecom and media company Vivendi SA's (VIV.FR) mobile unit SFR, the operator said it will split the role into two new operating regions; Northern & Central Europe and Southern Europe.

Vodafone's CEO for Italy, Paolo Bertoluzzo, has been given additional responsibility as CEO of the mobile operator's 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.

Mr Humm will start in his new role on Oct. 1, and Mr Bertoluzzo's 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 1028 GMT, Vodafone shares were steady at 181 pence, valuing the company at GBP89.08 billion ($138.39 billion), in a lower London market.

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