Mr. Bartle, 54, plans to focus on other business options that are as yet undecided.
The departure of Mr. Bartle as joint executive has been known by his founding partners, Nigel Bogle, 52, joint chief executive, and John Hegarty, 55, chairman-creative director, for the last two to three years.
"This has been in my plans for some time and I do feel this is the right time to move away and to make room for others," said Mr. Bartle.
"I suppose all good things come to an end, and this good thing could hardly have been better," he said.
Mr. Bartle's departure comes at a time when agency is expandinginternationally with new offices in New York and Singapore, and just 18 months after it sold a 49% stake to the Leo Burnett Co.
Mr. Bartle's 34-year career included an eight-year stint at Cadbury, where he latterly worked as marketing services manager, and as planning director of the London office of TBWA International, which he co-founded.
Bartle Bogle Hegarty, which has enjoyed a reputation as one of the U.K.'s leading creative agencies, was founded in 1982.
Renowned for his planning skills, Mr. Bartle was also president of the Institute of Practioners in Advertising between 1995 and 1997.
In a joint statement, Messrs. Bogle and Hegarty said, "There's no doubt that it's a significant moment when a 'name over the door' decides to leave, particularly when we've been together as long as we have. If these things have to happen, though, it's best if they do so when you are in as good a shape as we are and with the depth of management talent we have."
Copyright July 1999, Crain Communications Inc.