The lawsuit, filed on April 27, 2026, accuses Microsoft of anti-competitive practices related to its Teams business communication application, amid mounting legal and regulatory pressure on the company in European and American markets.
Slack Technologies and its affiliates stated that the lawsuit, filed on April 23, is based on what they described as Microsoft’s practices that restrict competition by integrating Teams into the Office suite, thereby limiting customer choice in the digital work tools market.
Previous European complaint against Microsoft:
In 2020, Slack filed a complaint with the European Commission, accusing Microsoft of using its Teams integration strategy within Office to gain an unfair advantage over competitors in the enterprise communications market.
Microsoft subsequently reached an agreement with the European Commission last year, pledging to adjust the pricing of its Office products not integrated with Teams, which helped it avoid potentially hefty fines.
Parallel class action in London:
The case coincided with a decision by London’s Competition Court to uphold a class action lawsuit accusing Microsoft of charging British companies high prices for using Windows Server through cloud computing services offered by rival companies.
(Reuters)

