Microsoft facing UK antitrust lawsuit from Slack over Teams 'bundling'

Salesforce and its workspace messaging app Slack are suing Microsoft at London's High Court over alleged anticompetitive practices relating to its Teams app.

Slack Technologies LLC and ‌related companies ⁠filed ⁠the lawsuit on April 23, which a Slack spokesperson said was "because Microsoft's practices harmed competition, using tying and bundling of Teams to limit customer choice".

Microsoft did not immediately ​respond to a request ⁠for comment.


Slack ‌had in 2020 complained to the European Commission, accusing Microsoft ⁠of bundling Teams with its Office product to gain an unfair advantage over rivals.

The U.S. software giant avoided a potentially hefty fine by promising reduced prices for Office products excluding Teams in an agreement ‌with the European Commission last year.

The filing of the lawsuit came ​in the ​same week ⁠that London's Competition Appeal Tribunal certified a mass lawsuit alleging Microsoft overcharged British businesses ​to use Windows Server software on cloud computing services provided by rivals.

Microsoft disputes the allegations made in that case.