• The French Competition Authority said Google has agreed to end some of its self-preferencing practices in the automated online advertising business.
• The investigation came after News Corp, newspaper Le Figaro and the press group Rossel filed a complaint against Google.
• Regulators across Europe are clamping down on the major U.S. tech giants.

France's competition watchdog fined Google 220 million euros ($268 million) on Monday for abusing its market power in the online advertising industry.

The French Competition Authority said Google had unfairly sent business to its own services and discriminated against the competition. Google has agreed to pay the fine and end some of its self-preferencing practices, the watchdog said.

The investigation found that Google gave preferential treatment to its DFP advertising server, which allows publishers of sites and applications to sell their advertising space, and its SSP AdX listing platform, which organizes auction processes and allows publishers to sell their "impressions" or advertising inventory to advertisers. Google's rivals and publishers suffered as a result, the regulator said.

Isabelle de Silva, president of the French Competition Authority, said in a statement the decision is the first in the world "to look at the complex algorithmic auction processes by which online advertising 'display' operates."

She added that the investigation revealed processes by which Google favored itself over its competitors on advertising servers and supply-side platforms, which are pieces of software used by publishers to manage, sell and optimize ad space on their websites and mobile apps.

"These very serious practices have penalized competition in the emerging online advertising market, and have enabled Google not only to preserve but also to increase its dominant position," said de Silva.

"This sanction and these commitments will make it possible to re-establish a level playing field for all actors, and the ability of publishers to make the most of their advertising spaces."

Google announced in a blog on Monday that it will be making a series of changes to its advertising technology.

"We recognize the role that ad tech plays in supporting access to content and information and we're committed to working collaboratively with regulators and investing in new products and technologies that give publishers more choice and better results when using our platforms," wrote Maria Gomri, legal director of Google France.

The investigation came after U.S.-based News Corp, French newspaper Le Figaro and the Belgian press group Rossel filed a complaint against Google.

Regulators across Europe are clamping down on the major U.S. tech giants amid concerns that they wield too much power on the bloc's 700 million-plus citizens.

Last week, Facebook was hit by antitrust probes from regulators in the U.K. and Europe.

The European Commission has launched investigations into Amazon, Google and Microsoft over the last few years, while the U.K.'s Competition and Markets Authority has also started probes into Google and Apple since it became an independent regulator in its own right in January following Britain's exit from the EU.