A source close to the pitch indicated that it was a statutory review.
The telecoms giant is reportedly looking to gain a head start on rivals China Mobile and China Telecom for its 3G network brand.
China Mobile reviewed its agencies earlier this year, after which ZenithOptimedia retained the account.
“3G competition is very intense in China, with 3G product information and noise flooding the market. Clients have put the agencies under a lot more pressure to compete in the changing market,” said one agency source.
MediaCom’s recent losses in China include Mars and Nokia, the latter part of a global realignment.