BEIJING — The Chinese authorities have warned major partners of Google’s China-based search engine that they must comply with censorship laws even if Google does not, an industry expert with knowledge of the notice said Sunday.

The Chinese government information authorities warned some of Google’s biggest Web partners on Friday that they should prepare backup plans in case Google ceases censoring the results of searches on its local Chinese-language search engine, said the expert, who did not want to be identified for fear of retaliation by the government.

The warning was the latest indication that two months of negotiations between Chinese officials and Google over government censorship have reached an impasse, making it more likely that Google will end up shutting down its Chinese search engine. The two sides have been at a standoff since Google announced in January that it planned to stop self-censoring the results of searches on its Chinese site, google.cn, in reaction to what it described as China-based cyberattacks on its databases and e-mail accounts.

The warning was intended to head off a wave of frustrated users should their Internet searches be stymied because of Google’s conflict with the government. Google controls nearly 30 percent of China’s Internet search market.