Murray will be replaced by Senior Independent Director Rijnhard van Tets who in turn will be succeeded by Non-Executive Director Thomas Thune Andersen in his current role.

"Whilst it is with great sadness that we accept his resignation, we understand his reasons and our thoughts and best wishes remain with him and his family," said Chief Executive Ayman Asfari in a statement.

(Reporting by Karolin Schaps; Editing by Li-mei Hoang)