BERLIN -- An effort to develop an easy way for consumers around the world to avoid being tracked and targeted by Internet advertisers appeared to hit an impasse Thursday, as privacy advocates and industry representatives accused each other of scuttling the process.
The closed-door meeting organized by W3C, the global standards group that promotes good governance of the Internet, failed to produce a consensus on how to allow consumers to simply and effectively declare their "do not track" preferences on Web sites. The talks foundered on main issues like the extent and types of data that advertisers could continue to collect even after consumers indicated they no longer wanted to be followed.
The conference, which concludes Friday, is not expected to produce a final resolution, and other meetings could be scheduled before the end of January, when the group is set to disband. But the stakes for Internet users are high and boil down to who determines the limits and protections of online privacy on the Internet: the businesses running the Web, which is largely the current status quo, or the consumers who use it.
For the moment, privacy advocates say the status quo is winning out.
"It seems the process has been hijacked by commercial interests," said Jacob Kohnstamm, the chairman of the European Commission's top privacy panel, the Article 29 Working Group. Mr. Kohnstamm's panel is an observer at the meetings, whose participants included about 40 Internet companies, advertising groups and privacy advocates.
Mr. Kohnstamm, who is also president of the Dutch Data Protection Authority, said proposals before the W3C would let advertisers continue collecting personal data through each mouse click, without obtaining prior consent.
"The Do Not Track standard would be utterly deceptive to users and act as a disguise for continuation of unfair and intransparent business practices," he said.
If adopted in this fashion, European regulators would then be left to police advertisers' actions, initiating proceedings based on their own investigations or on individual complaints, he said.
Advertising industry representatives attending the meetings were equally vocal in their displeasure over attempts to ban their ability to follow what people view online, which they argued would undermine the advertising-supported model used by most free services on the Web.
"This basically attacks the financing model of the Internet," said Dan Jaffe, the executive vice president of the Association of National Advertisers, a New York trade group representing 460 companies that spend $250 billion in advertising each year. "If these various proposals limit this type of advertising, it will cut down on the amount of free information that consumers have on the Internet, create incentives for online companies to erect pay walls, and lead to more shotgun forms of advertising."
Thomas Roessler, who is leading the meeting in Amsterdam for the W3C, said that several "open issues" remained to be solved, though he declined to specify which ones because the discussions were under way.
But he said the W3C, a group set up by one of the computer engineers who designed the World Wide Web, Timothy Berners-Lee, was optimistic that an effective compromise could be reached.
"I still have some measure of confidence we will come up with a workable solution," Mr. Roessler said.
The idea of giving consumers a simple and effective way to avoid being tracked by advertisers originated in 2011 at Mozilla, the makers of the Firefox Web browser. Currently, the only way consumers have to opt out of tracking is to visit Web sites sponsored by the ad industry like www.aboutads.info in the United States or www.youronlinechoices.com in Europe to request they no longer be followed. But not all Web sites honor those preferences.
"We are still optimistic we will get to a point where this becomes meaningful to consumers," said Alex Fowler, the global privacy and policy leader for Mozilla, which is participating in the forum in Amsterdam.
But he acknowledged wide differences among the participants, adding: "It might take more time than people are hoping in the short term."
In the United States, a failure by the W3C to establish an effective standard allowing consumers to opt out of tracking could prompt Congress to propose legislation addressing the issue, said Jon Leibowitz, the Federal Trade Commission's chairman, in an interview.
"There is enormous and bipartisan momentum for do-not-track options for consumers if there is no agreement by the end of this year," Mr. Leibowitz said.
While he said that it was "legitimate" for businesses to collect some information on Internet users, advertisers needed to allow consumers to establish some limits in how data were collected and manipulated.
"It is time to drop some of the bluster and work toward compromise," he said.
The effort to reach a consensus in Amsterdam has been complicated by conflicting U.S. and European legal approaches to online privacy. In the United States, the F.T.C. in 2011 exempted so-called first-party advertisers, which include the world's biggest Web businesses, including Google, Facebook, Microsoft and Apple, arguing that consumers effectively sanctioned their data collection by choosing to use their services.
Representatives for Google, Microsoft and Apple, which are participating in the talks, declined to comment.
But European law considers Internet tracking, whether done by first-party or third-party advertisers, to be illegal without explicit consent. Third-party advertisers typically put ads on the Web sites of other businesses.
The effect of tracking options on advertising is moderate. Only 10 percent of Mozilla's 450 million users worldwide have activated the do-not-track option on their browsers, while about 12 percent of people who have visited the do-not-track Web site in the United States have opted out.
A breakthrough appeared to be within reach last February when the F.T.C. announced that the Digital Advertising Alliance, the lead organization representing online advertisers, had agreed to abide and recognize a "do not track" option chosen by consumers, as long as consumers were required to actively request not to be followed.
But that fragile agreement was undermined in May when Microsoft announced that it would make "do not track" the default setting on its Internet Explorer 10 browser, which will begin shipping this month in Windows 8 operating system software.
Microsoft's decision raised the stakes in the debate, prompting industry associations like the Association of National Advertisers to join the W3C standards effort this summer.
While they may not act to stop it, most people do not want their Web movements tracked, said Jeffrey Chester, the head of the Center for Digital Democracy, a group based in Washington that advocates a stringent mechanism to end the collection of Internet users' data for manipulation in advertising.
The bigger problem, he said, is that the current proposals before the W3C have become so watered down that they could have no effect. That in turn would leave Europe with strict prohibitions on tracking and data collection, and the United States with few.
"We could end up with a two-track do-not-track system, which would help no one," Mr. Chester said.
Correction: October 4, 2012, Thursday
This article has been revised to reflect the following correction: An earlier version of this article incorrectly stated that Facebook did not participate in the W3C talks in Amsterdam. Facebook is participating in the summit.interact
This article originally appeared in The New York Times.