Au, who joined Digitas in 2006, took over the executive role in 2008 following the departure of Neil Runcieman, who founded and sold the Communication Central Group to the Publicis Groupe network Digitas in 2007.
At Digitas, Au has worked with brands including Absolut Vodka, the Intercontinental Hotel Group, Johnson & Johnson, HSBC and Philips.
She was previously GM of Digitas Shanghai and additionally worked at Grey Interactive and Bates.
Au’s departure comes after a year of changes for the digital agency. Last month, as part of Publicis’ Vivaki network, the holding group announced that it would consolidate Digitas and Razorfish’s international operations, and in July, Digitas experienced a global management reshuffle as CEO Alan Rutherford stepped down and global chief strategic officer and president of the Tribal DDB EMEA Stephan Beringer assumed his position.