Süreyya Ciliv has resigned as the CEO of Turkcell after eight years in charge of the Turkish operator.
Ciliv stepped down last week to be replaced by CTO İlker Kuruöz on an interim basis.
Turkcell said Ciliv's decision to resign was made for personal reasons, without commenting further.
It added that the search for a new Chief Executive was under way.
Ciliv departs after having presented the company’s highest ever recorded revenue and EBITDA in the third quarter of last year.
Group revenues rose six percent to TRY 3.1 billion (€1 billion) in Q3 thanks to higher mobile broadband uptake.
Turkcell is due to report full year results next week.
The Chairman of Turkcell Board of Directors, Ahmet Akça, commented: “Turkcell has achieved numerous milestones and success during Mr Süreyya Ciliv’s term of office.
“Mr Ciliv has lead the transformation of the GSM only company to a leading communication and technology company, both in Turkey and in the region.
“We would like to thank him for his valuable contributions and wish him every success in his future careers and personal life.”
For his part, Ciliv said: “We have always worked to create value for our customers, our stakeholders, the industry and our nation by facilitating access to knowledge with our technology, innovation and a strong team spirit.
“I would like to thank all of my team, our customers, our dealers, our suppliers, and our business partners who believed in and accompanied us on this journey. As I hand over my role, I truly believe that this strong team will take Turkcell forward.”