Yuen is an advertising industry veteran with over 20 years of brand-building and marketing management experience in Hong Kong, China and overseas.
He resigned as chairman of Ogilvy Hong Kong, where he worked from 2003 to 2010, in January last year.
Joining Fancl only one year ago, Yuen said that it was an interesting and rewarding working experience, but he believes "now is the right time to move on to pursue his other interests."
"I always see myself as a management scholar and I have been teaching MBA on a part-time basis for over 10 years," Yuen told Campaign Asia-Pacific, "My plan now is to teach MBA at the University of Hong Kong and the Fudan University in Shanghai as an adjunt professor before engaging something permanent."
Yuen has previously held client-side roles at both Ferrero and Hong Kong Futures Exchange.
The company is still looking for a replacement.
Reported in November, Fancl handed its US$18 million media account to Carat Hong Kong.