Europe’s love affair with Facebook may be coming to an end.

On Thursday, the European Union’s powerful antitrust officials fined the social network 110 million euros, or about $122 million, for giving misleading statements during the company’s $19 billion acquisition of WhatsApp, the internet messaging service, in 2014.

The fine — one of the largest regulatory penalties against Facebook — comes days after French and Dutch privacy watchdogs also ruled that the company broke strict data protection rules. Other European countries, notably Germany, also are clamping down on social media companies, including issuing potentially hefty penalties for failing to police hate speech and misinformation.

Margrethe Vestager, Europe’s competition chief, said on Thursday that Facebook had told the European Commission, the executive arm of the European Union, that the company could not combine the social network’s data with that of WhatsApp. The messaging service now has more than one billion users.

Yet last August, Facebook announced that it would now share WhatsApp data with the rest of the company. That potentially allowed it to gain an unfair advantage by combing through people’s online data, including internet messages and Facebook posts.

“Today’s decision sends a clear signal to companies that they must comply with all aspects of E.U. merger rules,” Ms. Vestager said in a statement on Thursday. “And it imposes a proportionate and deterrent fine on Facebook. The commission must be able to take decisions about mergers’ effects on competition in full knowledge of accurate facts.”

In response, Facebook said it had acted in good faith in its deliberations with Europe’s antitrust officials.

“The errors we made in our 2014 filings were not intentional,” Facebook said in a statement. “The commission has confirmed that they did not impact the outcome of the merger review.”