Vodafone Group Chief Information Security Officer Bryan Littlefair is leaving the operator and moving to insurance company Aviva.
The exec, who has been with Vodafone for more than seven years, is set to depart at the end of February.
Littlefair is in charge of the operator’s IT and network related information security activity.
No official announcement has been given about his departure but on his LinkedIn profile, Littlefair wrote: “Have really enjoyed my time at Vodafone, the security organisation has transformed over my tenure and I have made some great successes through having an excellent team focused on operational uplift and change.
“I have made some great friends for life, but looking forward to my next challenge at Aviva.”
The UK-based insurer has 31 million customers and operating capital generation of £1.3 billion in the first nine months of last year.
Intriguingly, Vodafone signed a seven-year, multi-million pound deal to provide Aviva with a range of communications solutions last July.
The news leaves another hole at the top of Vodafone after CTO Steven Pusey announced last week that he is set to retire.
Littlefair departs as competition in Vodafone’s home market is set to intensify.
Three UK owner Hutchison Whampoa confirmed on Friday that it is in exclusive talks with Telefónica about a €13 billion acquisition of O2.
BT is already in exclusive talks with EE about a merger.