Apple Inc.’s takeover of music-identification service Shazam faces an extended European Union probe as antitrust regulators flagged concerns that Apple might be able to lure rivals’ customers to its own music service.

The EU set a Sept. 4 deadline to investigate concerns that buying Shazam would give Apple access to commercially sensitive data about users of rival music-streaming services. It will also check if Apple Music competitors would be harmed if Apple were to stop Shazam referring customers to them.

"Access to such data could allow Apple to directly target its competitors’ customers and encourage them to switch to Apple Music," the EU said in an emailed press release. "As a result, competing music streaming services could be put at a competitive disadvantage."

The Shazam app uses the microphone on a smartphone or computer to identify almost any song playing nearby, then points users to places they can listen to it, such as Apple Music or Spotify Ltd.

The deal is one of Apple’s largest acquisitions, at a reported US$400 million according to people familiar with the transaction last year.