Google is facing a new antitrust investigation in Europe, with regulators probing whether the tech giant has manipulated the pricing of search engine advertising.

According to Bloomberg, The European Commission has sent letters to potentially affected businesses outlining concerns that Google may have “artificially increased the clearing price” in its ad auctions, potentially harming advertisers.

If proven, the conduct could breach EU competition rules and expose parent company Alphabet to fines of up to 10% of its global annual revenue.

The investigation is in its early stages but could soon be formally announced by EU Competition Commissioner Teresa Ribera (pictured).

Regulators have also issued requests for information to market participants, seeking feedback on Google’s position across multiple online advertising markets.

The European Union's competition commissioner, Teresa Ribera

Google, which has already been fined €9.5 billion (A$15.6 billion) by the EU in past antitrust cases, said its ad pricing is determined by a real-time auction system designed to deliver relevant ads.

“Google Search ads help small businesses compete with the biggest brands, driving economic growth and keeping the web free for everyone,” the company said in a statement. It added that auction pricing takes into account factors such as advertiser competition and ad quality.

The latest scrutiny adds to mounting regulatory pressure in Europe. Under the EU’s Digital Markets Act (DMA), Google has recently been ordered to remove technical barriers restricting rival AI search assistants on Android devices and to provide key data to competing search engines.

The company is also facing separate DMA investigations over allegations it favours its own services in search results and restricts app developers from directing users to offers outside the Play Store. Additionally, regulators are examining claims that Google unfairly demotes certain news results.