Microsoft Corp.’s "real relationship” with OpenAI is of high interest to European Union antitrust regulators, the bloc’s competition chief told Bloomberg TV.

The European Commission earlier this week said it’s examining whether Microsoft’s US$13bil investment into OpenAI should be vetted under EU merger rules, opening the risk of a full-blown investigation.

"What is interesting for us of course is what is the real relationship between OpenAI and Microsoft when it comes to control of the business in question,” Margrethe Vestager said Thursday in an interview with Bloomberg Television during a visit to the US.

The recent firing - and subsequent rehiring - of OpenAI Chief Executive Officer Sam Altman exposed just how linked the two companies have become. Microsoft shares which has invested more than US$13bil in the ChatGPT maker, negotiated directly for the return of Altman. Chief Executive Officer Satya Nadella even offered Altman and all other OpenAI employees jobs at Microsoft if they chose to leave.

Eventually, most of OpenAI’s board resigned and Altman was reinstated as CEO. Microsoft executive Dee Templeton also gained a seat as a nonvoting observer on OpenAI’s board.

The inquiry by the EU’s executive arm is part of broader call for feedback on competition issues that could arise in the area of generative artificial intelligence.

"This is very preliminary,” Vestager said about the EU looking into the Microsoft-OpenAI relationship, "but it is part of a larger endeavor to understand how AI will affect our marketplaces.”

"When we put in AI to that game, of course we see that this may accelerate some of the behaviors that we have seen and some of the things we have been concerned about,” she said.

Vestager is meeting with several US tech firms, including Alphabet Inc.’s Google, Apple Inc. and Nvidia Corp., during her US visit.

 - Bloomberg