Duriez said: "I will be running an office of 100 people with four times the revenues of the Philippines office.
China is a centre of excellence for OgilvyAction and BAT. It's a great opportunity for me."
A replacement head of IndoChina has yet to be announced, although it is understood the sub-region will be run by committee, with Southeast Asia head Peter Skalberg heading the operation.
Sandor moves to Manila in February, but will work across both markets to oversee the transition.
His first task will be to launch BatesAsia 141 Philippines, combining Bates with the existing 141 operation. He will team up with Cats Guerrero, the agency's general manager and ECD.
BatesAsia 141's Southeast Asia director Peter Skalberg, said: "Peter [Sandor] has done an outstanding job in getting some of the best talent in the advertising industry into our Indochina operations, as well as building up our portfolio with some of the top global and aspiring local brands.”
He added: “Pascal has successfully, with the support of Cats Guerrero, built a great operation. We wish him all the best in his new endeavour.”