London (CNN Business) Germany is moving to break up Facebook's dominant position in gathering data about social media users.

The country's antitrust office ruled Thursday that Facebook is abusing its virtual monopoly in social media by combining data from Instagram, WhatsApp and third party websites.

Facebook FB The office saidused the data to build a unique profile about each user to gain more market power.

In future, Facebook will have to seek German users' explicit consent to collect and combine such data. Germany's Federal Cartel Office ordered Facebook to come up with proposals for how to do this. If it doesn't comply, the regulator can impose fines of up to 10% of the company's annual turnover, or roughly $5.5 billion in this case.

"We are carrying out what can be seen as an internal divestiture of Facebook's data," said Andreas Mundt, the president of the antitrust office. "Facebook will no longer be allowed to force its users to agree to the practically unrestricted collection and assigning of non-Facebook data to their Facebook user accounts."

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