Global - Robert Lerwill will stand down as group CEO of marketing services group Aegis at the end of this month.
In a brief statement, Lerwill gave away little about his move but said he leaves the group in good hands, with a strong management team.
Aegis chairman John Napier will take on Lerwill's responsibilities on an interim basis.
Napier said Aegis Media and Synovate would be closely monitored as they face more "demanding and competitive market circumstances".
"The strength of Aegis is the performance of its two large international businesses: Aegis Media and Synovate," Napier said.
"They are both well-managed and we expect their combined 2008 operating results to be broadly inline with the average of current market expectations."