BRUSSELS -Apple faces an additional EU antitrust charge in the coming weeks in an investigation triggered by a complaint from Spotify, a person familiar with the matter said, a sign that EU enforcers are strengthening their case against the company.

The European Commission last year accused the iPhone maker of distorting competition in the music streaming market via restrictive rules for its App Store that force developers to use its own in-app payment system and prevent them from informing users of other purchasing options.

Such requirements have also come under scrutiny in countries including the United States and Britain.

Extra charges set out in a so-called supplementary statement of objections are usually issued to companies when the EU competition enforcer has gathered new evidence or has modified some elements to boost its case.

The Commission declined to comment. Apple had no immediate comment.

Spotify, the largest music subscription service in the world, is one of Europe's few global success stories in consumer technology.

  - Reuters