Wenzel assumes the role from his previous position as president and CEO of G1 Worldwide, a joint-venture between TBWA and Hakuhodo which services the Nissan Motor Company and its Nissan and Infiniti brands.
"I am happy to be getting back to building clients' brands in an environment where I have a more direct role and our team is fully responsible for our strategic thinking and creative product," said Wenzel, who joined G1 in 2001.
Kerwin, meanwhile, takes up the new position as director of TBWA/Korea's international division to handle its growing international business. His move comes after four senior TBWA staffers left the Seoul office earlier this year to start a new operation.