On Friday, Britain’s antitrust regulator provisionally concluded that Google’s parent company, Alphabet, had exploited its dominant position in digital advertising to limit competition. The Competition and Markets Authority (CMA) stated that Google used anti-competitive practices in open display advertising technology by favoring its own ad exchange, potentially harming thousands of UK publishers and advertisers.

Juliette Enser, the CMA’s interim executive director of enforcement, remarked that Google appeared to be leveraging its market power to stifle competition in online ads, which many businesses rely on to keep digital content affordable or free.

In response, Google disagreed with the CMA’s assessment, with its VP of Global Ads, Dan Taylor, defending the company’s advertising tools as vital for businesses to reach customers and generate revenue.

The U.S. Department of Justice and the European Commission are also investigating Google’s ad tech practices. The EU suggested Google might need to sell part of its ad tech business, though Google called this measure “disproportionate.”

The CMA indicated that Google had been abusing its dominance in ad supply since at least 2015, and it has the authority to impose fines of up to 10% of global turnover or issue binding orders to end the misconduct. Google’s response will be considered before the regulator decides on further action.