Tan will leave Aegis at the end of October and start work with The Star in November.
It's understood that he will be responsible for the media owner's digital infrastructure and properties. His role overlaps that of former digital business COO, Wong Siah Ping, who resigned in July.
So far, there has been no news of Tan's replacement from Aegis Malaysia.
Tan has been with the group for nearly a decade, joining Carat Interactive as managing director in 2004. Since then he has helmed both Carat Malaysia and Isobar Malaysia before taking on his current role mid-2012.