China's major search engine operators convened Thursday to sign an agreement of self-regulation, a move analysts said may not stop ongoing battles between Qihoo 360 Technology Co and Baidu Inc (3-B battles).

Twelve search engine players, including Qihoo 360, Baidu, and Tecent's search engine soso.com, attended a signing ceremony in Beijing Thursday afternoon, along with officials from the Ministry of Industry and Information Technology (MIIT), said the Internet Society of China (ISC) in a statement on its website.

An official from the MIIT refused to comment on the agreement when contacted by the Global Times Thursday.

The parties agreed to use the robots.txt protocol, an industry convention to tell cooperating search engines what information they can snatch from websites.

The protocol is designed, among other things, to protect sensitive information from search engine data mining.

For example, blogger Fang Zhouzi used his Sohu Weibo account to accuse Qihoo's search engine of mining users' personal data on October 9. The accusation has been under investigation by MIIT.

The ISC has been holding discussions with the major domestic search engine players since August, hoping to end the 3-B battles and restore the country's browser market, an ISC staff member who declined to be named told the Global Times.

The agreement came after Baidu filed a lawsuit on October 16 against Qihoo 360 for improper practices such as mining Baidu's data by violating the robots.txt protocol.

However, Qihoo 360 claimed in a statement sent to the Global Times Thursday that they have obeyed the protocols of other websites, while Baidu attempts to block Qihoo 360's access to the domestic browser market with a discriminatory protocol.

"We hope that this agreement will help forge a fair robots.txt protocol mechanism, instead of a competition tool for Baidu, the domestic search engine giant," Qihoo said.

Qihoo 360, a leading Chinese anti-virus software firm, launched its search engine hao.360.cn on August 16 and ranked second in market shares after Baidu within one week of operation, according to the Qihoo statement.

This aroused concerns among the domestic browsers. "Qihoo 360 is now both a player and a referee," said Wang Xiaochuan, CEO of search engine sogou.com, on its Sina Weibo account on September 2.

Baidu refused to comment on the agreement when contacted by the Global Times Thursday. Sogou.com and soso.com could not be reached by press time.

Experts said that despite the self-regulatory agreement, the 3-B battles will rage on.

"The government's interference might weaken the battle between Qihoo 360 and Baidu, but it won't eliminate the competition, which may be carried out more secretly in the future," You Tianyu, an analyst at Beijing-based Internet consultancy iResearch, told the Global Times Thursday.

"Such an industry agreement is not legally binding. It's more like a consensus obeyed voluntarily, and it's hard to define liability for the parties," Zhang Zhifeng, an independent intellectual property lawyer, told the Global Times Thursday.

A party caught breaking the agreement would be condemned only by public opinion, so corresponding regulations are necessary to protect users' rights and online search experience, said Zhang.

The lack of such regulations means Chinese Internet users have no legal recourse when harmed by the 3-B battles, Zhang noted, adding, "most of them are unaware that their personal data have been mined and made public."