BRUSSELS, Sept 25 Reuters Alphabet unit Google filed a complaint to the European Commission on Wednesday against what it said were Microsoft39;s anticompetitive practices to lock customers into Microsoft39;s cloud platform Azure.

Google, whose biggest cloud computing rivals are Microsoft and Amazon Web Services, said Microsoft was exploiting its dominant Windows Server operating system to prevent competition.

Google Cloud Vice President Amit Zavery told a briefing that Microsoft made customers pay a 400 markup to keep running Windows Server on rival cloud computing operators. This did not apply if they used Azure. Users of rival cloud systems would also get later and more limited security updates, Zavery said.

Google pointed to a 2023 study by cloud services organisation CISPE which found that European businesses and public sector bodies were paying up to 1 billion euros 1.12 billion per year on Microsoft licensing penalties.

Microsoft in July clinched a 20millioneuro deal to settle an antitrust complaint about its cloud computing licensing practices with CISPE, averting an EU investigation. However, the settlement did not include Amazon Web Services AWS, Google Cloud Platform and AliCloud, prompting criticism from the first two companies.

Microsoft said it had settled amicably similar concerns raised by European cloud providers, adding that Google had hoped they would keep litigating.

Having failed to persuade European companies, we expect Google similarly will…