The European Union is to launch a formal competition probe into Nvidia's planned $54 billion takeover of British chip designer Arm.
That's according to Reuters sources.
The investigation is expected to begin after Nvidia officially notifies the European Commission of its plan to acquire Arm.
Britain's competition regulator said last week that the deal could damage competition and weaken rivals.
And pushed for a further lengthy investigation.
Nvidia says the "transaction will be beneficial to Arm", and that it looks "forward to engaging with the Commission."
Arm did not immediately respond to a Reuters request for comment.
It's currently owned by Japan's SoftBank Group, and is a major player in global semiconductors.
The sector is fundamental to technologies from artificial intelligence and quantum computing, to 5G telecoms networks.