London (CNN) — The European Union has launched investigations into Apple, Google and Facebook parent Meta on suspicion that they are failing to comply with a new landmark European law designed to promote competition in digital services.

The European Commission said it “suspects” that various practices by all three companies “fall short of effective compliance” with the Digital Markets Act (DMA), which went into effect earlier this month. If the probes find a “lack of full compliance,” they could face “heavy fines,” said European Commissioner Thierry Breton.

The DMA requires dominant online platforms to give users more choices and rivals more opportunities to compete. It currently applies to the three tech giants under investigation, as well as Amazon (AMZN), Microsoft (MSFT) and ByteDance, the Chinese parent company of TikTok.

By mid-May, the list could also include Elon Musk’s X and Booking.com, the EU has said.

Violations of the new law can lead to stiff penalties, including fines of up to 10% of a company’s global revenue and up to 20% for repeat offenses. For most of the regulated companies, that would translate to tens of billions of dollars.

The practices the European Commission is investigating include what it calls Meta’s “pay or consent” approach. Last October, Meta (METAlaunched a subscription service, called “Subscription for no ads,” allowing European users of Facebook and Instagram to pay up to €12.99 ($14) a month for ad-free versions.

“The Commission is concerned that the binary choice imposed by Meta’s ‘pay or consent’ model may not provide a real alternative in case users do not consent, thereby not achieving the objective of preventing the accumulation of personal data by (large companies),” the body said in a statement.

A Meta spokesperson responded: “Subscriptions as an alternative to advertising are a well-established business model across many industries, and we designed ‘Subscription for no ads’ to address several overlapping regulatory obligations, including the DMA. We will continue to engage constructively with the Commission.”

CNN has also contacted Apple (AAPL), Google and its parent Alphabet (GOOGL) for comment.

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