Swansea Council chief executive Tim Thorogood has resigned with immediate effect.
He said: 'I have enjoyed three challenging and stimulating years working for Swansea. I had originally intended working for Swansea for no longer than five years and I have decided in the circumstances simply to leave at this point to develop my career in a different direction.
'Both the council and the city have achieved much in the past few years - Swansea is definitely a place with a future.
'I am grateful for the opportunity to have made an important contribution, both in terms of improved management and performance for the council and in the delivery of successful regeneration projects for the city.
'I am particularly proud of the efforts of staff across the board to improve our services and of the council's delivery of the Liberty Stadium and key improvements in the city centre. I'm sure that the new leisure centre will be a great success.'
Chris Holley, council leader, said:
'Tim has made a huge contribution to Swansea in the three years that he has been chief executive.
'He has been the inspiration and driving force behind many improvements to the council and has laid the groundwork for the council to become a top performing organisation.
'On behalf of all members of the council I wish him every success in the future.'