(Reuters) - Chinese authorities are investigating the country's top anti-virus software firm Qihoo 360 Technology after a prominent blogger criticized its web browser, alleging improper practices such as mining of user data, Qihoo said in a posting on its official microblog account.
The company, which has taken on Chinese search engine leader Baidu Inc in that country's browser market, also said in the posting on Thursday that it would bring a lawsuit against Baidu, accusing it of conducting a smear campaign through the blogger, a charge that Baidu denies.
Baidu spokesman Kaiser Kuo told Reuters on Friday that the firm has no relationship with the blogger, Fang Zhouzi, and declined to comment on the lawsuit threat.
Fang could not be reached for comment while calls to a Qihoo spokesman and the Ministry of Industry and Information Technology (MIIT), which is conducting the investigation, were not answered.
"We hope that the MIIT can have speedy completion of this investigation and that the investigation is objective and impartial and will show Qihoo's innocence," Qihoo Chief Executive Zhou Hongyi said in a microblog posting.
Qihoo has achieved some success in wooing users away from Baidu and Google Inc, achieving 5 to 10 percent of user traffic since its launch in August, according to data from Analysys International.
Qihoo is no stranger to bruising Internet battles, having fought over competition issues with Tencent Holdings Ltd in late 2010. More recently, Qihoo threatened to sue U.S. online stock commentary website Citron Research over negative reports it had issued.
(Reporting by Melanie Lee; Editing by Edmund Klamann)