Google's ad tech practices face opposition from the British competition regulator.

• The Competition and Markets Authority claimed on Friday that Google has harmed competition by favoring its own ad tech services through its dominance in online display advertising.
• The regulator expressed concern that Google is favoring its own services through its dominance in the sector.

The U.K.'s competition authority has issued a statement of objections against Google's ad tech practices, which it provisionally believes are harming competition in the country.

The Competition and Markets Authority claimed that the U.S. internet search giant has harmed competition by favoring its own ad tech services through its dominance in online display advertising.

According to a 2019 study by the CMA, the vast majority of the U.K.'s publishers and advertisers use Google's technology to bid for and sell space to display ads in a market where players were spending £1.8 billion annually.

Regulators are concerned about technology giants, such as Google, preferencing their own services through "self-preferencing."

Google's ad technology competitors are at a disadvantage due to the company's actions, which prevent them from competing on a fair and equal footing.

Online advertising helps businesses keep their digital content free or cheaper by reaching millions of people across the UK, aiding in the buying and selling of goods and services, as stated by Juliette Enser, interim executive director of enforcement at the CMA on Friday.

Publishers and advertisers, who provide the funding for free content, need to have effective competition and fair deals when buying or selling digital advertising space, according to Enser.

Google did not immediately respond to a CNBC request for comment.

The European Union has accused Google of violating antitrust rules in ad tech and may consider breaking up parts of its business to address their concerns.

In August, a federal judge ruled in favor of the Justice Department, finding that Google has maintained a monopoly on search and text advertising for an extended period.

The recent ruling against a tech company, which is the first anti-monopoly decision in years, has been likened to an antitrust judgment against Microsoft, which established that the company had unlawfully utilized the market power of its Windows operating system to suppress competition from rival browsers, specifically Netscape Navigator.

The CMA ruled on Friday that Google has been abusing its dominant position as the operator of "Google Ads," "DV360," and "DoubleClick For Publishers" since 2015, in order to boost the market position of its advertising exchange, AdX.

Ad exchanges are technology platforms that enable the buying and selling of media advertising inventory by fielding requests for bids from publishers and matching them with responding bids from advertisers through an auction process.

Google charges its highest fees to advertisers on AdX, which is the "centre of the ad tech stack" for the company, with the CMA stating that Google takes roughly 20% of the amount for each bid that's processed on its platform.