The European Union accused Microsoft of breaching antitrust rules by tying its Teams product to its popular Office 365 and Microsoft 365 productivity applications. The EU opened an investigation into Microsoft in July 2023 following a complaint by Slack, which has a rival chat service to Teams. Microsoft took steps to unbundle Teams from Microsoft 365 last year to address antitrust concerns, but the EU says these changes were insufficient. Microsoft faces a potential fine of up to 10% of its global revenue if found to have breached antitrust rules.