BRUSSELS - EU antitrust regulators opened on Tuesday an investigation into Alphabet unit Google's digital advertising business to examine whether the company favors its own business, putting rivals, advertisers and online publishers at a disadvantage.

"The formal investigation will notably examine whether Google is distorting competition by restricting access by third parties to user data for advertising purposes on websites and apps, while reserving such data for its own use," the European Commission said in a statement.

Reuters reported exclusively last week that the EU competition enforcer would investigate lucrative digital advertising business before the end of the year.

Google generated $147 billion in revenue from online ads last year, more than any other company in the world. Ads on its properties, including search, YouTube and Gmail, accounted for the bulk of sales and profits.

About 16% of revenue came from its display or network business, in which other media companies use Google technology to sell ads on their website and apps.

  - Reuters