Peter Papadimitropoulos has quit as group chief executive of Millennium and Copthorne hotels (M&C) after just six months.
A statement by the group said he had left "by mutual consent with immediate effect."
He is the third chief executive of the hotel chain to leave within the last three years.
His departure came as the group announced a 52% rise in pre-tax profits to £55.2m for the first half of 2007 compared with £36.1m for the same period in last year.
Mr Papas - as he is known in the industry - joined M&C on March 1.
He took over from Tony Potter who served two years as ceo, leaving in January and citing family reasons. Mr Potter is now ceo of Corinthia Hotels based in Malta.
He in turn took over from John Wilson in 2004.
Mr Kwek Leng Beng, chairman of M&C was quoted in the London Financial Times as saying that Mr Papas' approach did not match that of the company's.
"We have a different style of management and leadership. We just have mutual consent that we should go our separate ways," Mr Beng said.
Wong Hong Ren, an executive director of M&C, will act as Interim group chief executive until a permanent replacement is found.
The group has 112 hotels located in the Americas, Europe, Middle-East, Asia and New Zealand. They include the Biltmore in Los Angeles and the Mayfair in London.
It said that its hotel group for the first six months of 2007 had an operating profit of £58.9m, £8.7m up on the figure of £50.2m for 2006.
Group revenue per available room (revPAR) rose by 8.9% to £50.70, average room rates grew by 8.9% to £69.26 but occupancy remained flat.
London where it has five properties, achieved the "strongest growth" with a 13.8% increase in revPAR to £78.34 and a 15% increase in average room rate and occupancy slightly up to 84.1%.
In France and Germany where the company has four hotels, it said revPAR fell by 5.6% to £47.89.
It said the year started with weak results in Germany where 13.2% fewer rooms were sold and revPAR decreased by 14.7%