The Competition and Markets Authority said Friday it was seeking views from interested parties to comment on whether the two firms recent collaboration could result in competition issues in the UK. The move from the UK watchdog comes less than two months since it eventually approved Microsoft's acquisition of Activision Blizzard.

Microsoft is the largest investor in OpenAI, having invested $13 billion into the startup so far. The software giant has incorporated several of OpenAI's products into its suite of enterprise tools, and the startup spends considerable amounts on Microsoft's cloud services.

The CMA said it will look at whether the the balance of power between the two firms has fundamentally shifted to give one side more control or influence over the other.

When asked to comment on the CMA's move a spokesperson at the European Commission said the regulator had been "following very closely the situation of control over OpenAI."