China will require that Web filtering software be included with all computers sold in the country, another step up in its efforts to control pornography and other content on the Internet.
The move follows a government crackdown on online smut that has led to the closure of thousands of Web sites this year, and concern that such campaigns could expand to target content that is political rather than pornographic.
PC makers will be required to pre-install the Web site-blocking program or offer it on a CD-ROM included with all PCs sold in China after July 1, according to a translation of a Ministry of Industry and Information Technology notification seen by IDG News Service.
The move is meant to protect youth from "unhealthy" information online, according to the statement.
The program, called Green Dam Youth Escort in Chinese, blocks only sites with pornographic content, and parents can turn it off, said Bryan Zhang, general manager of Jinhui Computer System Engineering, which designed the software.
But the measure triggered concern about wider censorship.
China blocked access to Web sites including Microsoft's Bing search engine last week, adding to a list of previously banned sites including YouTube and some blog services. Twitter and Hotmail were also blocked ahead of the 20th anniversary last week of Beijing's bloody crackdown on democracy protests, though those Web sites could load again on Monday.
Dell will consider including the software with new PCs only if its purpose is to block pornographic content from children, and only if it can be disabled, said Amit Midha, Dell's president for Greater China.
It will not install software that helps censor other Internet sites, Midha said. Midha also said Dell had not heard of any Chinese government notification ordering the program's use.
Dell is the third-biggest PC vendor in China, according to research company IDC.
Lenovo and Hewlett-Packard, China's number one and two PC vendors, declined to comment.
Image recognition technology lets Jinhui's program block individual images in addition to Web sites when they resemble sample pornographic images in a database, said Zhang, the company's manager. Users are notified when updates are available for download, he said.
Jinhui's Web sites says its program also prevents the use of proxy servers or circumvention software to visit banned sites, measures often used by savvy Internet users in China.
China's government will pay for the first year of the program's use for all PC buyers, after which they can buy the program from Jinhui, Zhang said.
Jinhui has previously worked with a research institute under China's public security ministry on a blocking system for "harmful" online video clips, and has "long-term technical cooperation" with the army's Information Engineering University, according to its Web site.
Jinhui won a government tender to distribute its software with PCs about a year ago, and has since worked with PC vendors to ensure compatibility and proficiency with the software, said Zhang.
The company has also worked with the government to put its software on PCs in schools, and hopes to market the product abroad, he said.
(John Ribeiro in Bangalore contributed to this story.)