An agreement involving Washington and nine other states will require the nation’s leading Internet-advertising service to better inform consumers when the company gathers information about the web-surfing activities of Internet users, state Attorney General Christine Gregoire said.

Under the agreement filed in Thurston County Superior Court, New York-based DoubleClick Inc. will make it easier for consumers to know when their visits to particular Web sites are being tracked through the use of “cookies.”

For example, Web sites that contract with DoubleClick will have to inform consumers in their privacy policies that DoubleClick is using cookies. Furthermore, consumers will be able to sign up for automatic notice of any change in DoubleClick’s privacy policies.

“Cookies create a record of a web surfer’s travels like footprints in the sand,” Gregoire said. “This agreement with a major Internet advertiser will go far toward helping consumers guard their privacy on line.”

The information about the user’s web-surfing habits can then be used to target specific advertising to that web surfer.

Because many online advertisers and Web sites contract with DoubleClick for services, nearly every computer is tagged with DoubleClick cookies at one time or another.

The agreement with DoubleClick ends a 30-month investigation.

Under the agreement, a third party will evaluate how well DoubleClick conforms to its own privacy policy and its agreement with the states. The company is also working on development of a “cookie viewer” that will enable consumers to see the information stored on their computers that allows DoubleClick to aim specific advertising.

Other states involved in the DoubleClick settlement are New York, California, Connecticut, Michigan, Arizona, Kansas, Massachusetts, New Jersey and Vermont.