Sina, the largest Chinese-language infotainment web portal, has abandoned the Google search service and started using its own search technology instead, according to foreign media reports.

The two companies announced a partnership back in 2007 to help Google battle China’s dominating search engine, Baidu. Under the terms of the agreement, Under the terms of the agreement, Google provides Web page search services for Sina.com. In return, Google shared the advertising revenue generated by traffic from China’s most-visited portal.

In recent news however, Liu Qi, Sina’s vice president of marketing, stated that the Internet portal shifted its search service because the contract between Sina and Google has already expired. Sina’s own search engine, iAsk, which used to serve only vertical search, or specialized search, is now on the home page of Sina.com as the main search engine for news, blogs and music.

Sina removed the Google search service using its own search technology 520x312 Sina abandons Google, starts using its own search service

Google’s relationship with the country hasn’t exactly been smooth sailing. Google’s decline in the Chinese market began at the start of 2010 when the company announced it might leave the country after being the victim of a cyber attack that it said originated in China. This followed the company’s move to stop censoring search results in China by redirecting all users from its Google.cn page to its unfiltered Hong Kong search engine. Google and the Chinese government are in the midst of a dispute over the responsibility for the slowdown of Gmail in China.

Google’s share of search traffic in China continues to decline. Last year, Google fell to 19.6% in the fourth quarter from 21.6% in the previous. It peaked at an unimpressive 35.6% in the last three months of 2009, according to Chinese market research firm Analysys International.