Google on Tuesday formally announced its plans to enter the Chinese market and establish a development center in China - and appointed Kai-fu Lee as its new head for Chinese operations and the new center - one day after it was sued by Microsoft for having hired away Lee, a former Microsoft corporate vice-president, Xinhua reports.

The search giant said China, the world's second-largest internet market in terms of online users, is one of the most important in its plans to expand globally. Its new head in China has "extensive and intensive relations with the Chinese Government, scientists and engineers," according to Xinhua.

During his tenure at Microsoft, Lee was one of Chairman Bill Gates's most-trusted technical advisers and is among the world's foremost researchers in speech-recognition technology, reports reports Business Week. Lee's work at Microsoft aimed to "topple Google as king of the search-engine mountain," according to Business Week.

Microsoft accused Lee of violating his noncompete clause and Google of "intentionally assisting" Lee despite knowing that he had agreed to the clause. "It's a particularly egregious violation of our noncompete agreement," says Tom Burt, Microsoft's deputy general counsel. "There has been no effort made to observe that agreement."

Microsoft says it wants a court order forcing Lee and Google to abide by terms of confidentiality and non-competition agreements Lee signed at Microsoft- and it wants Lee barred from disclosing any Microsoft trade secrets or other confidential information, reports USA Today.

Google responded with a statement on Tuesday, saying Microsoft's claims are "meritless" and vowing to defend Lee with its full support.