LONDON (AP) — European Union regulators have opened an antitrust investigation into Facebook to look into whether the company distorts competition in the classified advertising market by using data it collects from rival services.

The EU's executive commission said Friday that it's also looking at whether the way Facebook's embeds its own classified ad service, Marketplace, into the social network, gives it an advantage in reaching customers, in violation of EU competition rules.

The investigation is the latest salvo by EU regulators trying to rein in the dominance of big tech companies and highlights their longstanding concern that the data these online platforms collect from their customers is used to compete against them.