Joe McDonald, AP Business Writer

BEIJING (AP) -- China postponed a plan to require personal computer makers to supply Internet-filtering software Tuesday, retreating in the face of protests by Washington and Web surfers hours before it was due to take effect.

Manufacturers would have been required to include filtering software known as Green Dam with every computer produced for sale in China starting Wednesday.

The Ministry of Industry and Information Technology said the plan would be delayed in part because manufacturers had trouble meeting the deadline. It gave no indication whether it might be revived later.

The postponement was a rare reversal by the communist government, which seemingly gave in to the combined pressure of angry Chinese Web users, Washington and computer makers.

The controversy reflected the tussle between the ruling party and an increasingly informed, vocal public and industries that provide jobs and taxes that are crucial to the government's rule.

Top U.S. trade officials had protested the plan and the haste with which it was announced as a possible trade barrier. Industry groups warned that the software might cause security problems. Free-speech advocates attacked the plan as censorship.

American diplomats met earlier with Chinese officials to express concern about the plan.

"I think the cost of the move from trade friction and generally a public relations black eye was becoming pretty clear to the government," said Duncan Clark, chairman of BDA China Ltd., a Beijing research firm.

The postponement "gets them out of the scrutiny of the international media and business," Clark said. Chinese authorities said Green Dam is needed to shield children from violent and obscene material online. But analysts who have reviewed the program say it also contains code to filter out material the government considers politically objectionable.

Chinese Web surfers ridiculed the software and circulated petitions online appealing to Beijing to scrap its order. They said Green Dam would block access to photos of animals and other innocuous subjects.

News of the announcement spread in China quickly via Twitter and the Chinese mini-blogging site Fanfou. Wen Yunchao, a Chinese blogger who has been among the most vocal critics of Green Dam, said he did not believe the announcement marked an end to the plan.

"They are using the word 'delay,' instead of saying they stopped the plan," Wen said. "I think that it's possible that at some point in the future the government could still enforce their policy and install software on personal computers that filters the information people are able to look at. So, I am calling this an intermediary victory."

"For now, we will go ahead with the original plan, which was to distribute the software," she said. "Moving forward, we will pay attention to future developments." The Green Dam initiative coincides with a tightening of government controls on Internet use.

___ Associated Press Writer Alexa Olesen and Associated Press researcher Bonnie Cao in Beijing contributed to this report.