After two years as JWT's Hong Kong CEO, Dennis Wong will be succeeded by a new leadership team.
Dennis Lam (pictured), director of client service, will take on the general manager role with Mark Webster promoted to non-executive chairman for the agency.
In a statement, Wong said he was resigning for personal reasons.
"It is very unfortunate that I have to take a break because of my personal and family reasons, otherwise I would definitely not leave the agency that I really enjoy working for," he said.
He will stay on until the end of August to ensure a smooth transition.
"With the talent that we have, and their commitment and passion, together with the support of regional and North Asia management, I'm sure JWT Hong Kong will be going from strength to strength," Wong added.
JWT Asia Pacific CEO Tom Doctoroff praised Wong, saying he had unified the agency.
"I wish Dennis (Wong) all the best. In the last two years, he has unified our agency, in terms of product aspiration and culture," said Doctoroff.
"This is a legacy that will endure well into the future."
JWT Asia Pacific's management team, including Doctoroff, Asia Pacific Creative Council Chairman Lo Sheung Yan, North Asia Executive Creative Director & China Chairman Yang Yeo, and Asia Pacific Director of Strategic Planning Ratan Malli, who are all based in Shanghai, will continue to work closely with the team in Hong Kong.