BRUSSELS—European Union antitrust authorities on Monday opened a full-blown probe into Apple Inc.’s proposed acquisition of the popular song-recognition app Shazam Entertainment Ltd. on concerns the deal could reduce choice for users of music-streaming services.
The proposed acquisition, which the EU has the power to block, would give Apple ownership of an app that helps users identify songs before directing them to Apple Music or Spotify AB to listen to and potentially buy or stream them. The proposed deal also would give...