AMSTERDAM, Nov 14 (Reuters) - The European Commission on Thursday said hotel reservation website Booking.com must now comply with strict EU obligations, following its designation as a "gatekeeper" under the Digital Markets Act in May.

The Digital Markets Act $(DMA)$ is one of the most stringent regulations targeting tech giants' market dominance, imposing tougher obligations to moderate content, allow fair competition and make it easier for consumers to switch between services.

It designates companies with more than 45 million monthly active users and 75 billion euros ($79 billion) in market capitalisation as gatekeepers, providing a core platform service for business users.

If a gatekeeper does not comply with the DMA, the Commission can impose fines of up to 10% of the company's total worldwide turnover, which can go up to 20% in case of repeated infringements. It can also impose limits on takeover activity.

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(Reporting by Bart Meijer)

((Bart.Meijer@thomsonreuters.com;))