Tony Hughes, president and ceo of Radius Travel, has resigned.
He will be replaced by Allan Slan, previously executive vp and interim ceo while the company launches a search for his permanent successor.
Mr Hughes joined Radius six years ago with the remit of transforming the agency network into a global travel management company.
Mr Hughes said that with this job complete, "now is the logical time for change."
Radius currently has combined annual sales of its 92 shareholders of $19bn. It operates in 80 countries and has regional offices for the Americas, EAME and Asia Pacific.
Mr Hughes, a Briton, worked for P&O Travel which was a founder member of Radius, for 14 years.
Before that he worked for Thomas Cook and Hogg Robinson. He is also a former chairman of the UK Guild of Business Travel Agents now the Guild of Travel Management Companies.
Bill Tech, chairman of the Radius board, said: "We are extremely grateful to Tony for his service and wish him well in his future endeavors.
"Tony has left the Company with a well-defined, long-term strategy capable of seizing upon the multiple opportunities that are now open to it worldwide."
Sol Melia profits rise
Spanish hotel chain Sol Melia announced a 16.1% rise in net profits for the fist nine months of 2007 to €141.9m.
It also said it had bought the German hotel chain Innside which has eight leased properties in Berlin, Munich, Frankfurt, Düsseldorf and Bremen and four more due to be opened between 2008 and 2010 in Vienna, Berlin, Dresden and Düsseldorf.
Sol Melia said the purchase "significantly increased its presence in Germany, its third most important feeder market, from 16 to 28 hotels."
The Spanish chain said the investment would cost €16.5m.
Sol Melia said revenues for the first nine months were €1,022m, a 6% rise on the same period in 2006, while pre-tax profits increased by 2.3% to €271.4m.
The group said a good summer in Spain as well as its city hotels doing well around the world accounted for the improvement.