Slack filed a complaint with the European Union over alleged unfair competition by Microsof Teams.

Slack, a US corporate office communications software start-up, said today it had lodged a complaint with the European Commission against Microsoft, alleging unfair competition. Slack said in its complaint that Microsoft abused its market dominance to eliminate competition for its team collaboration communications product, Microsoft Teams, by bundling it with its popular Office office software.

Slack said Microsoft’s move meant that millions of people were forced to install Microsoft Teams and could not remove it.

Slack filed a complaint with the European Union over alleged unfair competition by Microsof Teams.

Microsoft Teams is a smart, chat-based team collaboration tool that simultaneously shares documents and provides instant messaging tools for members, including voice, video conferencing, and more. Slack runs a similar product.

Industry insiders say Slack’s complaint stems from previous setbacks for the company. Stewart Butterfield, Slack’s chief executive, said in an interview in May: “Microsoft may not be happy to focus on killing us, and Microsoft Teams is a tool to do that.” “

Still, Mr Butterfield said earlier that Microsoft Teams was not a competitor to Slack, although the company listed it as a major competitor in a filing with the Securities and Exchange Commission.