By EMILY STEEL

Seeking to head off escalating scrutiny over Internet privacy, a group of online tracking rivals is building a service that lets consumers see what information those companies know about them.

The project is the first of its kind in the fast-growing business of tracking Internet users and selling personal details about their lives. Called the Open Data Partnership, it will allow consumers to edit the interests, demographics and other profile information collected about them. It also will allow people to choose to not be tracked at all.

When the service launches in January, users will be able to see information about them from eight data and tracking firms, including BlueKai Inc., Lotame Solutions Inc. and eXelate Inc.

Additional tracking firms are expected to join once the system is live, but more than a hundred tracking firms and big Internet companies including Google Inc. and Yahoo Inc. are not involved.

The companies involved represent some of the most aggressive trackers of Internet users, many of which have been profiled in The Wall Street Journal's "What They Know" series about online privacy.

"The government has told us that we have to do better as an industry to be more transparent and give consumers more control. This is a huge step in that direction," said Scott Meyer, CEO of Better Advertising Project, a New York-based start-up that is directing the Open Data initiative.

The $25 billion Internet advertising industry is scrambling to make more transparent its widespread practice of collecting, selling and using Web browsing and other profile information about consumers, as part of a broader effort to ward off federal regulation.

Online tracking is legal, and companies currently aren't bound by government rules to show people what they know about them.

Internet and advertising companies typically gather information about users to target ads. A person's Web activities and location can be used to tailor the type of credit cards pitches they see, for instance.In a report on Internet privacy on Wednesday, the Federal Trade Commission called for the development of a do-not-track tool system that would enable people to avoid having their actions monitored online—a move the online advertising industry opposes.

BlueKai trades data on more than 200 million Internet users, boasting the ability to reach more than 80% of the U.S. Internet population.

The new Open Data initiative marks the first time consumers will have a one-stop-shop to see all the information these companies know about them.

Previously, a handful of Internet and tracking firms, including Google, Yahoo, BlueKai, Lotame and eXelate, made such information available on their own sites. However, few consumers were aware.

"Not all consumers know who eXelate is, but if we can create a central portal where eXelate and all our lovely competitors can be in one place, it provides an easier way for consumers to get access to these tools," said Mark Zagorski, chief revenue officer at eXelate.

A website, betteradvertising.com, will list online data and tracking firms that have collected or used information about a person's interests, Web browsing or other details.

For the companies that sign up for the initiative, a person will be able to see what information they have collected, Mr. Meyer says.

Users also will be able to access their profiles via advertisements that display an icon: a lowercase "i" encased in a triangle. Clicking on the icon displays more information about how the ad was targeted to a user and further clicks provide more information about how to see the information that the companies know about users and how to opt-out.

A visitor can see, for instance, that eXelate has pegged them as a person interested in buying a hybrid or luxury automobile, with a household income of $60,000 and an interest in shopping for personal technology. That user can change the income bracket or remove it entirely from his profile.

Users also can decide not to be tracked.

The information displayed as part of the Open Data initiative also won't be shared and used for tracking purposes. However, some of the companies will show only broad categories in which they classify users rather than the minute details that they know.

Better Advertising says it is not charging the data companies to be a part of the service, which is free to consumers. Advertisers ultimately will have to pay for the service that places the Open Data icon and information in their ads.