01:01 PM EDT, 04/18/2024 (MT Newswires) -- (Updates with Microsoft ( MSFT ) declines to comment in the fourth paragraph.)

Microsoft's ( MSFT ) $13 billion investment in OpenAI could face an antitrust investigation as regulators in the EU are building a case for such scrutiny, Reuters reported Thursday, citing unnamed sources.

The EU antitrust regulator had decided not to investigate the partnership under EU merger rules, but Microsoft ( MSFT ) could still be subject to an antitrust investigation to determine if its relationship with OpenAI restricts or distorts competition within the single market, the report said.

No decision has been reached on the matter because EU regulators are looking for evidence and may ultimately choose not to investigate, the report said.

Microsoft ( MSFT ) declined MT Newswires' request for comment.

The company's shares fell 1% in recent trading Thursday.

(Market Chatter news is derived from conversations with market professionals globally. This information is believed to be from reliable sources but may include rumor and speculation. Accuracy is not guaranteed.)