Telefonica Deutschland CEO Thorsten Dirks will leave at end-Q1 2017 after the company agreed to his request for an early termination of his contract.

No reason was given for his early departure —  Dirks’ contract was meant to run until September 2017.

“Following his material contribution to the successful integration and transformation of the company, with a strong position and strategy in place, Thorsten Dirks will turn to new challenges in 2017,” said a statement.

“The  supervisory board will deal with the matter of the succession immediately and make an announcement in due course,” it went on, adding that Dirks will “ensure a smooth handover” before he leaves.

Eva Castillo, chairperson of the supervisory board, thanked Dirks “for the exceptional collaboration and successful development of the company.”

Dirks was previously CEO of E-Plus Group, and became CEO of Telefonica Deutschland in October 2014 when the two firms merged.

At the time, he had set out 2017 as the date when the new entity would have parity with its two competitors, T-Mobile and Vodafone.

“It has been a privilege to lead Telefonica Germany throughout the merger. We have laid out the foundation for a very successful future for the company,” he said at the time.