Google  (Nasdaq: GOOG) said Thursday it's joining other Internet companies such as Yahoo, Microsoft and AOL to  enable users to limit collection of their personal data, by making a do not track button available on Web browsers.

The companies agreed to stop using information about a customer's Internet viewing habits to customize ads or use data for credit, employment, insurance or health care reasons. But the information can still be used for market research and product development, according to the Mountain View, Calif., giant.

We're pleased to join a broad industry agreement to respect the 'do-not-track button' to be embedded in its Web browser, letting users restrict the amount of data that can be collected about them, Google's senior vice president of advertising, Susan Wojcicki, said in a statement.

The agreement will be enforced by the Federal Trade Commission. But since the move by Google is voluntary, the company could essentially back out of the agreement as long as the F.T.C. was given fair notice, according to Ian DiBernardo, a partner with Stroock & Stroock & Lavan in New York.

A lot of times, these changes are driven by changes in technology, he said in an interview.

The move comes after President Barack Obama's administration announced a Privacy Bill of Rights for Internet users. Among other things, the White House plan would require Internet companies to make privacy policies easy to understand, demand that consumers be allowed to limit the information collected, enable them to see data that is collected and request corrections if needed.

The Internet has become an engine of innovation, business growth and job creation, so we need a strong foundation of clear protections for consumers, and a set of basic principles to help businesses guide their privacy and policy decision, Commerce Secretary John Bryson said in a statement.

Internet companies have received much scrutiny regarding their privacy policies. Last November, Facebook agreed to a settlement with the F.T.C. over accusations that it made information about users public even though the social-networking company had said the data would remain private. Facebook agreed to make several changes to its privacy policy and submit to inspections.

Google came under fire last week after researchers at Stanford University reported the company was tracking users of Apple's iPhone and Safari browser by circumventing tracking-prevention software in those products.

While privacy advocates generally lauded Google's decision, some said the agreement doesn't go far enough to ensure consumer privacy.

It's a good start, Christopher Calabrese, legislative counsel at the American Civil Liberties Union, told the Wall Street Journal. But we want you to be able to not be tracked at all if you so choose.

The Electronic Privacy Information Center has long supported the do not track button, David Jacobs, a Consumer Protection Fellow at the center said in an interview. But he said it would be preferable if legislation were written into law mandating the feature instead of companies voluntarily.

But obviously this is better than nothing, he said.

Shares of Google fell $2.33 to $605.61 in mid-afternoon trading.