A small Chinese hi-tech firm is suing Microsoft for alleged intellectual property rights violations in its latest Windows Vista operating system, the second lawsuit launched in China this year against the US software giant for alleged patent violations.

China E-Commerce Info-Tech Co Ltd (CECIT), based in Xi'an, Shaanxi Province, accused Microsoft of using its RSS (Really Simple Syndication)-related technology in Vista without licensing agreements.

"We applied for the invention patent of our self-developed method to use the RSS service in 2005 and received patent certificate (No ZL 2005 1 0022721.3) from the State Intellectual Property Office (SIPO) last December," said Wang Jianbo, chairman of CECIT.

The Xi'an Intermediate People's Court has accepted the case and held the first hearing last month.

Microsoft China appeared in court but denied the violation, according to Wang.

CECIT is requesting Microsoft stop the alleged violation and halt the distribution of Vista with the RSS function within China.

Microsoft was unavailable for comment yesterday.

Last year Beijing-based Zhongyi Electronic Ltd brought Microsoft to court, accusing the US firm of using its inputting technology and fonts in Windows operating systems without commercial agreement for a decade.

Such lawsuits could be embarrassing for Microsoft, which is currently fighting software piracy in China.

The firm later applied for a patent review committee under SIPO to invalidate Zhongyi's patent but was rejected.