The European Commission (EC) accused Microsoft of breaching antitrust rules by bundling its Teams messaging and videoconferencing app with its business software, giving it an unfair advantage over rivals such as Slack.

The EC informed Microsoft that by tying Teams with the tech giant’s Office 365 and Microsoft 365 applications it is “restricting competition on the market for communication and collaboration products”.

“Preserving competition for remote communication and collaboration tools is essential as it also fosters innovation on these markets,” stated Margrethe Vestager, EC EVP for competition policy.

Following a complaint from Salesforce-owned Slack, the EC opened an investigation into Microsoft in 2023.

To address antitrust concerns, Microsoft spun-off Teams from its commercial Office products across the EU and Switzerland in August 2023. Those changes that were implemented in April 2024.

However, the EC’s preliminarily investigation found the move “insufficient to address its concerns and that more changes to Microsoft’s conduct are necessary to restore competition”.

Microsoft could be fined up to 10 per cent of its annual worldwide turnover. The EC could also impose remedies if it decides additional steps are needed to restore competition.

“Having unbundled Teams and taken initial interoperability steps, we appreciate the additional clarity provided today and will work to find solutions to address the Commission‘s remaining concerns,” stated Microsoft President Brad Smith in an email to Mobile World Live.

The EC noted there is no legal deadline for it to complete its inquiries into Microsoft’s alleged anticompetitive conduct.