Sean Rach managing director of OgilvyOne and Neo@Ogilvy Hong Kong is departing the agency after nine years with his position to be succeeded by general manager Kitty Wong.
Royce Yuen, president for Ogilvy Hong Kong, said Rach's contribution to the group has been remarkable.
"He has helped to build a company that is best of its class in terms of market reputation and creative awards. OgilvyOne is the undisputed leader under his leadership," Yeun said.
Client marketers have ranked OgilvyOne as the top digital agency in Marketing's annual Agency of the Year survey since 2007.
Wong will be promoted as managing director of OgilvyOne Hong Kong following Rach's departure.
"Kitty has been with us for a decade and has been a close partner to Sean. She will provide the continuity that we need, there is no one more suitable than Kitty to take over the leadership of OgilvyOne in Hong Kong," Yuen added.
Marketing understands the agency is busy alerting its staff and clients ahead of an expected media announcement.
Clients that the agency will be keen to put at ease will include Vodafone which recently stabled its entire creative business with OgilvyOne.
Rach has been with Ogilvy for the past nine years, he has masterminded the launch of Neo@Ogilvy in 2007 and was made chairman of the Mobile Marketing Association in July 2009.