EU Commissioner of Competition Margrethe Vestager | John Thys/AFP via Getty Images Vestager set to sanction Facebook Commission concludes social network misled officials during $21-billion acquisition of WhatsApp.

Margrethe Vestager, Europe's competition commissioner, is expected to levy fines against Facebook on Thursday after concluding the social network misled officials during its $21-billion acquisition of WhatsApp, according to people familiar with the case.

Vestager already ruled out unpicking the deal, but any sanction could be several multiples of the €20 million imposed on Electrabel in 2009 for failing to notify the Commission of its takeover. POLITICO reported Friday the Commission had wrapped up its investigation.

Misleading officials carries a maximum fine of 1 percent of annual revenues — or about €250 million in this case.

Facebook would be the latest giant U.S. tech firm to fall victim to Vestager, who has adopted decisions against Amazon and Apple, and is running three cases against Google.

Vestager formally charged the social network in December with misleading her officials after the firm merged its user accounts with those of WhatsApp. Facebook said it would use the information to make better “friend” suggestions and show users ads that were more relevant, but the move appeared to contradict statements Facebook made during the merger review that it was unable to automatically merge accounts.