EU authorities have launched an in-depth investigation into Apple's proposed takeover of UK music recognition app Shazam.
The European Commission said it was concerned that the deal would reduce choice for users of music streaming services, given that it combines two "significant and well known players" in the digital music industry.
It highlighted that Apple Music has become the second largest music streaming service provider in Europe, while Shazam offers the leading music recognition app for mobile both in the European Economic Area and worldwide.
There are worries that Apple would gain access to commercially sensitive data about competitors' customers as a result of the takeover.
"Access to such data could allow Apple to directly target its competitors' customers and encourage them to switch to Apple Music. As a result, competing music streaming services could be put at a competitive disadvantage," the Commission said.
"In addition, while at this stage the Commission does not consider Shazam as a key entry point for music streaming services, it will also further investigate whether Apple Music's competitors would be harmed if Apple, after the transaction, were to discontinue referrals from the Shazam app to them.
It was confirmed in December that Apple was buying Shazam, in a deal reported to be worth around £300 million.
Competition commissioner Margrethe Vestager said: "The way people listen to music has changed significantly in recent years, with more and more Europeans using music streaming services.
"Our investigation aims to ensure that music fans will continue to enjoy attractive music streaming offers and won't face less choice as a result of this proposed merger."
EU authorities now have until September 4 to take a decision on the takeover.