The move would knock $23.8 billion off the social network's market value of $538 billion as of Friday's close and shares in other social media companies including Twitter Inc and Snap Inc also dipped in early deals in New York.

One Wall Street analyst said the reports raised 'systemic problems' with Facebook's business model and a number said it could spur far deeper regulatory scrutiny of the platform.

The head of European Parliament said on Monday that EU lawmakers will investigate whether the data misuse has taken place, adding the allegation is an unacceptable violation of citizens' privacy rights.

Facebook was already facing new calls for regulation from U.S. Congress and questions about personal data safeguards after the reports from the New York Times and London's Observer over the weekend.