Robbie Keane has issued a statement after resigning as manager of Ferencvaros.
The Irishman has been widely linked with the Celtic vacancy this summer.
Keane led Ferencvaros to the Hungarian title during his first season with the club, and won the Hungarian Cup this term.
"After an incredibly enjoyable and successful 16 months at Ferencvaros, I have made the difficult decision to bring my time at the football club to an end," Keane wrote on Instagram.
"From the beginning, the President, the Board, the staff, and the players made me feel welcome and were a pleasure to work with. Together, we formed a fantastic partnership that delivered great success for the club, and I am incredibly proud of what we achieved.
Read more:
"The supporters at Ferencvaros are among the most passionate in Europe, and the backing they have given me from the moment I arrived is something I will always remember and cherish.
"Winning the League in my first season, followed by lifting the Magyar Kupa last week, are moments I will always be immensely proud of. I will also never forget those unforgettable nights during our unbeaten run in the Europa League. These are achievements that will stay with me for the rest of my career.
"After a great deal of thought and reflection, I believe now is the right time for me to move on. It is not a decision I have taken lightly.
"Ferencvaros is a special football club and I have no doubt it will continue to enjoy success in the years ahead.
"Thank you all for your incredible support and the unforgettable moments we shared together. I wish the club and everyone connected to it nothing but the very best for the future."
Interim Celtic manager Martin O'Neill will hold talks with principal shareholder Dermot Desmond over the permanent position next week.
Alongside Keane, Craig Bellamy and Roberto Martinez have been linked to the role.
