US workspace messaging app developer Slack Technologies on Wednesday asked European antitrust regulators to investigate Microsoft for allegedly abusing its market dominance.

Slack said the issue was Microsoft’s Teams productivity software, which has seen a surge in demand as employees work remotely due to lockdowns aimed at slowing the spread of the coronavirus.

It said it has filed a complaint against Microsoft with the European Commission. Teams competes with Slack and Zoom Video Communications, both of which have also reported increased demand for video calling.

“Microsoft has illegally tied its Teams product into its market-dominant Office productivity suite, force-installing it for millions, blocking its removal, and hiding the true cost to enterprise customers,” Slack said in a statement.

Its general counsel, David Schellhase, accused Microsoft of reverting to past behaviour.

“They created a weak, copycat product and tied it to their dominant Office product, force-installing it and blocking its removal, a carbon copy of their illegal behaviour during the ‘browser wars’,” he said.

To be assessed

The European Commission, which has fined Microsoft a total €2.2-billion in a decade-long investigation involving tying cases and other practices, confirmed receipt of the complaint, saying that it would assess it under its standard procedures.