BEIJING: China's leading Internet search engine, Baidu, has filed a lawsuit in a New York court against a US firm that managed its domain registration, Baidu said in a statement on Wednesday.

Baidu's website was paralyzed for several hours after a cyber-attack on January 12, denying users from many places around the world access.

The attackers posted on the site a message in red saying, "This site has been hacked by Iranian Cyber Army."

It is believed the unidentified "Iranian Cyber Army" changed Baidu's domain name server records and redirected traffic to another website.

"Register.com, Inc.'s gross negligence resulted in severe damage to the company," said the statement.

The company declined to detail its losses and it failed to disclose the damages it is seeking.

The search engine, which claims 70 percent of China's Internet search market, had only been down only once previously, for half an hour in December 2006.