SAN FRANCISCO -- An Internet industry code of ethics intended to safeguard online freedom of speech around the world is to be adopted this week by technology titans including Google, Yahoo and Microsoft.

The US-based Center for Democracy & Technology told AFP that two years spent collaborating with Internet firms on rules of conduct will come to fruition in the coming days.

The code of ethics is a voluntary framework to help protect people who express opinions online in countries such as China, where talk of democracy or criticism of the Communist government is treated as criminal behavior.

Yahoo launched the talks with industry partners, academics, human rights groups and investors to promote a code of behavior for global technology and communication companies operating in "challenging markets."

"We seem to be getting more grey areas in terms freedom of expression versus censorship, legal versus illegal and border versus non-border," Yahoo chief executive Jerry Yang said while promoting cyber rights in Washington this year.

Yahoo was thrust into the forefront of the online rights issue after the California company helped Chinese police identify cyber dissidents whose supposed crime was expressing their views online.

Google has been criticized for complying with Chinese government's demands to filter Internet searches in that country to eliminate query results regarding topics such as democracy or Tiananmen Square.

Internet firms contend they must comply with China’s laws in order to operate there. Yang has called for the US government to devote itself to a political solution to the problem.

The code of conduct is to call on Internet firms to narrowly interpret government requests for information or censorship and to fight to minimize cooperation.