According to the Commission, Meta abused its dominant position in the market for personal social networks by tying Facebook Marketplace to Facebook.

All Facebook users automatically have access and get regularly exposed to Facebook Marketplace, whether they want it or not.

The Commission found that competitors of Facebook Marketplace may be foreclosed as the tie gives Facebook Marketplace a substantial distribution advantage which competitors cannot match.

It also said Meta unilaterally imposes unfair trading conditions on other online classified ads service providers who advertise on Facebook and Instagram. This, it says, allows Meta to use ads-related data generated by other advertisers for the sole benefit of Facebook Marketplace.

The Commission has imposed a fine of €797.72 million on Meta, which has said it will appeal.

Margrethe Vestager, the Commission’s executive vice-president in charge of competition policy, said: “Today we fine Meta €797.72 million for abusing its dominant positions in the markets for personal social network services and for online display advertising on social media platforms.

“Meta tied its online classified ads service Facebook Marketplace to its personal social network Facebook and imposed unfair trading conditions on other online classified ads service providers. It did so to benefit its own service Facebook Marketplace, thereby giving it advantages that other online classified ads service providers could not match.

“This is illegal under EU antitrust rules. Meta must now stop this behaviour.”

In a statement, Meta said: “This decision ignores the realities of the thriving European market for online classified listing services and shields large incumbent companies from a new entrant, Facebook Marketplace, that meets consumer demand in innovative and convenient new ways.

“We will appeal this decision to ensure that consumers are well served in the EU.”

It added: “It is disappointing that the Commission has chosen to take regulatory action against a free and innovative service built to meet consumer demand, particularly when senior European political figures are calling for the EU to be more competitive, innovative and forward-thinking.”