Jean-Yves Charlier has resigned as CEO of VEON, leaving the operator scrambling to find a new leader.
The Frenchman (pictured) leaves after three years in the role, with no clear reason given for his departure.
VEON has made Supervisory Board Chairman Ursula Burns Executive Chairman in the interim, putting her in direct control of the executive team.
The operator has also made Head of Major Markets Kjell Morten Johnsen acting COO to assist Burns.
It said the search for a replacement to VEON was underway.
Charlier leaves a month after reporting revenues and EBITDA rose 1.9 percent and 7.5 percent respectively last year.
He said: “It has been a privilege to lead VEON through a critical period in its history.
“Over the past three years, we have achieved a profound transformation of the Group and I am immensely proud of all that we have accomplished.
“The transformation creates a solid foundation for a positive path for the company in the years ahead and I wish Ursula and the VEON teams across the world the very best.”
Burns, the former Chairman and CEO of Xerox, joined last summer with part of her remit being to “reinforce” VEON's corporate governance and culture of compliance.
She joined at the same time as former Vodafone UK Chief Executive Guy Laurence, who took on a director role.
VEON’s Head of Emerging Markets and Head of Eurasia left last month, while its Chief Performance Transformation Officer departed in December.
Burns said: “With VEON’s unique geographic footprint, and a strong push on our digital agenda to better serve our 240 million customers, we are well positioned to compete, grow and prosper in the markets we serve.
“I look forward to working even closer with VEON’s management team to build on our strong foundations and find further opportunities to unlock value for our shareholders.”