Exclusive: Google's adtech business set to face formal EU probe by year-end - sources

A sign is seen at the entrance to the Google retail store in the Chelsea neighborhood of New York City, U.S., June 17, 2021. REUTERS/Shannon Stapleton

BRUSSELS (Reuters) - Alphabet 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.