BRUSSELS (AP) — The European Union announced Thursday that it opened a formal antitrust investigation targeting Microsoft into the software company's Teams messaging and videoconferencing app over concerns that its bundling with its Office productivity sofware suite gives it an unfair edge over competitors.

The European Commission, the 27-nation bloc's top competition enforcer, said that it would carry out its in-depth investigation “as a matter of priority.”

The investigation stems from a complaint filed in 2020 by Slack Technologies, which makes popular workplace messaging software.

Slack, owned by business software maker Salesforce, alleged that Microsoft was abusing its market dominance to eliminate competition — in violation of EU laws — by illegally combining Teams with its Office productivity software suite.