Sohu.com has threatened to sue Google for violating its intellectual property rights, and renewed a demand for the company to stop downloads of a Chinese software tool based, in part, on one of its own databases.
"We are very sorry that a leading US company like Google, which comes from a country that respects intellectual property rights, has exhibited a complete disregard for intellectual property in China," Sohu said.
"We demand Google stop infringing on Sogou Pinyin Input Method Editor (IME) intellectual property and cease downloads and the operation of Google Pinyin IME, otherwise we will bring legal charges against Google," the statement said.
A Google China spokeswoman did not immediately respond to a request for comment. Earlier, the company acknowledged it had used part of a Sohu database in its Pinyin IME, saying it was "inadvertently" incorporated into the software.
IMEs allow users to type Chinese characters using their Pinyin romanisation equivalents, and are found on most computers in China.
While similar tools have been around for years, Sohu was the first to draw on a database of popular search queries, compiled by its Sogou search engine, to predict which Chinese words and names a user is looking for. The improved speed and accuracy that resulted from this technique made the Sogou Pinyin IME, released last year, a favourite of millions of Chinese Internet users.
In addition, the tool offers a search button that links to the Sogou website and is visible on a user's desktop almost all the time. That helps explain why Google developed a competing product.
Google released its Pinyin IME last week and users soon discovered it was based, in part, on a dictionary of Chinese words and names drawn from the Sogou Pinyin IME. Faced with overwhelming evidence that it had copied parts of Sohu's dictionary, which had not been made public or licensed for use outside Sohu, Google made changes to its dictionary over the weekend and issued an apology to Sohu. Google has not offered an explanation for how it obtained Sohu's database.
On Friday, Sohu sent a letter to Google, demanding the company stop downloads of the Google Pinyin IME, issue an apology and discuss compensation for Sohu or face legal action. While Google's recent actions appeared to satisfy some of those conditions and avoid the possibility of a legal battle, Sohu feels the US internet company has not gone far enough in making restitution.
Sohu's criticism of Google's respect for Chinese intellectual property rights comes at an awkward time. On Monday, the US Trade Representative announced plans to bring a World Trade Organization complaint against China, charging that the country has not done enough to protect copyrights held by US companies.