The European Union’s antitrust regulators have warned Google over practices involving its Android mobile operating software, Reuters reported over the weekend, citing a 150-page EU document sent to complainants last week.

In their “statement of objections” sent to Google in April, the bloc’s regulators reportedly accused Google of paying phone makers to preinstall Google search exclusively on their devices. The regulators, who also argued that Google cannot “punish or threaten” smartphone makers for not pre-installing its apps, plan to order the company to cease its practices.

According to the document seen by Reuters, the anti-competitive practices, which began in 2011, are still ongoing, and the company may even face a hefty fine.

“The Commission intends to set the fine at a level which will be sufficient to ensure deterrence,” the document reportedly said.

This is not the first time Google has run afoul of antitrust laws in the EU. In April, the bloc’s competition commissioner Margrethe Vestager accused the U.S. tech giant of abusing its dominant position in the market by forcing cellphone manufacturers to install its apps in return for access to Google Play Store. Then, in July, the European Commission filed an antitrust charge against the company for using its Adsense advertizing business to restrict some websites from displaying ads from Google’s competitors.

“We believe that our innovations and product improvements have increased choice for European consumers and promote competition,” Google said at the time. “We’ll examine the commission’s renewed cases and provide a detailed response in the coming weeks.”

Alphabet — Google’s parent company — was initially given 10 weeks to respond to the charges leveled against it in July, but the deadline has since been extended to October 13, according to a report by the Agence France-Presse.