BRUSSELS, June 13 (Reuters) - Alphabet's Google was hit with a complaint by Austrian advocacy group NOYB on Thursday for allegedly tracking users of its Chrome Web browser, an issue already on EU antitrust regulators' radar.

The U.S. tech giant is phasing out the use of third-party cookies that advertisers use to track consumers in order to protect consumer privacy.

It has introduced a set of tools called the Privacy Sandbox to block covert tracking techniques and limit data sharing with third parties while developers and publishers can measure ads without tracking individual users.

Chrome users are asked whether they want to turn on the ad privacy feature or not to prevent being tracked.

NOYB (none of your business) said the feature allows Google to track users within the browser, and that the company should first seek users' consent as required under European Union privacy rules.

"People thought they were agreeing to a privacy feature, but were tricked into accepting Google's first-party ad tracking. Consent has to be informed, transparent and fair to be legal. Google has done the exact opposite," NOYB founder Max Schrems said in statement.

The group on Thursday filed a complaint with the Austrian data protection authority.

NOYB has filed scores of complaints with EU and national privacy watchdogs against big tech companies for alleged privacy infringements.

A Google spokesperson defended the company's position, saying Google had improved ways to protect people's privacy.

"This complaint fails to recognize the significant privacy protections we've built into the Privacy Sandbox APIs, including the Topics API, and the meaningful privacy improvement they provide over today's technologies, including third-party cookies," said the spokesperson.

"Privacy Sandbox is designed to improve user privacy and provide the industry with privacy-preserving alternatives to cross-site tracking. We’ve been closely engaging with privacy and competition regulators globally, and will continue to do that to reach a balanced outcome that works for users and the entire ecosystem," added the spokesperson. (Reporting by Foo Yun Chee Editing by Mark Potter)