Google partners in China have begun severing ties with internet firm since it announced it was redirecting Chinese language searches through Hong Kong to bypass mainland censorship rules.
The move comes less than a week after a group of partners in China called on the internet firm to provide some clarity around its plans, saying the uncertainty was hurting their businesses.
Tom Online, which is owned by Hong Kong billionaire Li Ka-shing, is among the first to cut ties with Google, and there are indications that others will follow, according to US reports.
Media companies in China have also warned that advertisers may switch to rivals for fear of falling into disfavour with Chinese authorities and especially if the number of Google users falls sharply.
Shares in Baidu, the biggest internet search operator in China, rose 2.6% on the day after Google announced it was circumventing China's censorship rules.
Baidu accounted for 58.6% of China's online search market in the last quarter, compared with 35.6% for Google, according to research company Analysys International.
Google said in January it was no longer willing to censor content on its Chinese site after it was among more than 20 US companies targeted by China-based hacking attacks.
Google said hackers used highly sophisticated attacks to access company information and data on e-mail accounts belonging to human rights activists connected with China.
China has criticised Google strongly for its anti-censorship move, but said there should be no wider effect on Chinese-US ties, provided there is no political interference by the US.
Analysts said both countries appear keen to limit the row and to restore good relations after months of tension.