Several makers of personal computers including Acer, Lenovo and Sony, are providing the porn blocking Green Dam software with models sold in the country's market, despite a government decision to postpone a plan to make the Internet filtering system mandatory.

Others are still evaluating the software and are not currently providing it.

China recently announced a delay in a requirement that the software be pre-installed or supplied with all computers sold in China, according to the Ministry of Industry and Information Technology.

"We took action before the Green Dam order was postponed so we will continue it," said a Lenovo official. The country's top PC manufacturer said it would offer the software pre-installed or on disk.

Other makers, including Acer, Sony and Haier, are shipping Green Dam on disks with computers for sale in China.

Green Dam, developed by the Zhengzhou-based Jinhui Computer System Engineering Co, became controversial after concerns were raised over security loopholes, its effects on computer performance and privacy issues.

Hewlett-Packard, the world's top PC maker, and Dell Inc said they were not providing Green Dam with their PCs in China.

In the Buynow electronics mall in Xujiahui, few consumers wanted Green Dam on their computers, PC distributors said yesterday.

Green Dam is already in use in some Internet cafes and schools and is available as a free download. It was designed to protect children from violence and pornography and to help parents control the time their children spent online.