The review is the FMCG giant's third in an ongoing process in the region. A Taiwanese review is expected by the end of the year.
Unilever's media planning business is currently with Initiative, while Asatsu-DK and Hakuhodo hold the media buying account.
Initiative is pitching against MindShare and the two Japanese incumbents for the combined account.
The review follows the departure of Initiative's Tokyo president and Unilever business director, Rob Fitzgerald, who is relocating to the US to become the director of Initiative's New York operation.