After 22 years at Marsh UK, Mike Hammond has decided to leave the broker for "family reasons", effective 1 July 2003, the company said.
Hammond, who shared the chief executive role with Philip Gregory, felt he needed to leave for personal reasons even though Marsh offered him other positions.
A Marsh spokeswoman said: "After much deliberation, he has decided that the lifestyle these positions would require do not fit with his family commitments."
Though speculation still remains over whether rival broker Willis is searching for a new UK chief executive, Marsh stressed Hammond was not leaving to join a rival and will "remain committed" to Marsh.
Marsh Ltd, which includes all Marsh UK operations and Ireland, will now be controlled by Bruce Carnegie-Brown acting as chief executive officer (CEO) for all of its UK operations, effective 2 June 2003.