LONDON — The European Union is escalating its scrutiny of the artificial intelligence industry, including taking a fresh look into Microsoft’s multibillion-dollar partnership with OpenAI, a top EU official said Friday.

The European Commission, the bloc’s executive arm, started reviewing the deal last year to see whether it broke EU merger rules but dropped it after concluding that Microsoft hadn’t gained control of OpenAI, Margrethe Vestager, the commission’s executive vice president for competition policy, said in a speech.

“Microsoft has invested $13 billion in OpenAI over the years,” she said. “But we have to make sure that partnerships like this do not become a disguise for one partner getting a controlling influence over the other.”

She signaled that the commission would take another tack to examine the deal, and the industry more broadly. It’s using the bloc’s antitrust rules, which target abusive behavior by companies that have a dominant market position.

The commission sent information requests in March to big AI players including Microsoft, Google, Facebook and TikTok, reviewed those replies and is “now sending a follow-up request for information on the agreement between Microsoft and OpenAI,” Vestager said.

The EU wants “to understand whether certain exclusivity clauses could have a negative effect on competitors.”

A Microsoft spokesman said: “We appreciate the European Commission’s thorough review and its conclusion that Microsoft’s investment and partnership with OpenAI does not give Microsoft control over the company. We stand ready to respond to any additional questions the European Commission may have.”

OpenAI didn’t respond immediately to a request for comment.

The stepped-up scrutiny highlights how European Union regulators have been pacesetters for the global push to rein in big tech companies, including the major AI players.