KEY POINTS
  • Regulators plan to investigate whether Facebook Marketplace and Facebook Dating have had an unfair advantage over competitors.
  • Two investigations were launched on Friday by the U.K. and Europe.
  • Facebook said it will cooperate fully with the investigations to "demonstrate they are without merit."
In this photo illustration, the Facebook logo is seen on a smartphone screen with the EU flag in the background.

LONDON — Regulators in the U.K. and the EU launched formal competition investigations into Facebook at the same time on Friday, marking a rare coordinated probe of a big U.S. tech firm.

The U.K.'s Competition and Markets Authority said it is investigating whether Facebook is abusing a dominant position in the social media or digital advertising markets through its collection and use of ad data.