The European Commission (EC) launched an investigation to assess Apple’s proposed acquisition of Shazam, expressing concerns the deal could reduce choice for users of music streaming services.

Competition Commissioner Margrethe Vestager said the probe “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.”

Apple lined up the acquisition of the company, which developed the popular music recognition app, in a bid to bolster its Apple Music streaming service and step up competition with major rivals Spotify and Google.

While financial terms of the deal were not disclosed, the price tag is reported to be $400 million, which would make Shazam Apple’s largest acquisition since it bought headphone maker Beats Electronics for $3 billion in 2014.

The EC said in a statement it was concerned “Apple would obtain access to commercially sensitive data about customers of its competitors for the provision of music streaming services in the EEA.”

This would allow it to directly target competitors’ customers and encourage them to switch to Apple Music.

The commission also wants to look at what would happen if Apple decided to stop the app from referring its rivals. The EC said it has until 4 September to investigate.

In February Austria, France, Iceland, Italy, Norway, Spain and Sweden called for the investigation to assess whether the deal complied with EU Merger Regulation.

The EC has a duty to assess mergers and acquisitions involving companies with a turnover above certain thresholds and to “prevent concentrations that would significantly impede effective competition in the EEA or any substantial part of it”.