European Union regulators have opened a formal investigation into claims that Microsoft is unfairly bundling its Teams video conferencing app with its popular Office software as Brussels intensifies its scrutiny of big technology groups.

The European Commission, the executive body of the EU, said on Thursday that it feared Microsoft “may be abusing and defending” its market dominance in productivity software “by restricting competition.”

It was concerned the US tech giant may grant Teams “distribution advantages by not giving customers the choice” over access to the product, the statement said.