Microsoft’s financial support of ChatGPT maker OpenAI could be subject to merger rules in the European Union, EU antitrust authorities said on Tuesday, echoing a similar warning from their British counterpart in December, Reuters reported.

The U.S. software giant, which last year pledged to invest more than $10 billion in OpenAI without voting rights, said it does not own any part of OpenAI.

The European Commission previously stated that it is closely monitoring the development of the situation.

“The European Commission is examining whether Microsoft’s investment in OpenAI can be reviewed under the EU Merger Regulation,” the European Commission, which acts as the EU’s competition enforcement body, said in a statement.

Microsoft said its partnership with OpenAI, cemented in 2019, has fostered AI innovation and competition while maintaining the independence of both companies.

“The only thing that has changed recently is that Microsoft will now have a non-voting observer on the OpenAI board of directors,” a Microsoft spokesperson said.

The commission said that some deals agreed between major digital market players and developers and suppliers of generative artificial intelligence are under investigation for their impact on market dynamics. It did not mention the names of the companies.

Also on Tuesday, the Commission gave interested parties until March 11 to provide feedback on competition in virtual worlds and generative artificial intelligence.