Sources: Google's Adtech Business Set to Face Formal EU Probe by Year-End

Alphabet (GOOGL.O) unit Google could face its biggest regulatory threat, with EU antitrust regulators set to open a formal investigation into its lucrative digital advertising business before the end of the year, said people familiar with the matter.

It would mark a new front by the EU competition enforcer against Google. It has in the last decade fined the company more than 8 billion euros ($9.8 billion) for blocking rivals in online shopping, Android smartphones and online advertising.

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