Illustration of Microsoft and Activision Blizzard logos
Microsoft logo is seen on a smartphone placed on displayed Activision Blizzard logo in this illustration taken January 18, 2022. Reuters

Microsoft's president Brad Smith said the UK regulator's decision to prevent its acquisition of 'Call of Duty' maker Activision Blizzard "had shaken confidence" in Britain as a destination for tech businesses.

The Competition and Markets Authority (CMA), which operates independently from government, blocked the deal on Wednesday, saying it could hit competition in the nascent cloud gaming market.

Microsoft hit back on Thursday, saying it was "probably the darkest day in our four decades in Britain" and sent the wrong message to the global tech industry about the UK.

"If the government of the United Kingdom wants to bring in investment, if it wants to create jobs (...) it needs to look hard at the role of the CMA, the regulatory structure in the United Kingdom, this transaction, and the message that the United Kingdom has just said to the world," he told BBC radio.

A spokesman for British Prime Minister Rishi Sunak said Smith's comments were "not borne out by the facts".

"We continue to believe that the UK has an extremely attractive tech sector and a growing games market," he said. "We will continue to engage proactively with Microsoft and other companies."

Smith said Microsoft had worked effectively with regulators in Brussels but not in London, which he said refuted Britain's claim that it would be more flexible after Brexit.

The company had answered the CMA's questions, he said, and it had told them to come back with any more concerns. "They went silent, we heard nothing from them," he said.

"There's a clear message here - the European Union is a more attractive place to start a business if you want some day to sell it than the United Kingdom," he added.

But CMA Chief Executive Sarah Cardell said the regulator's role was to make sure Britain was a competitive environment for businesses to be able to grow and thrive.

"The decision that the CMA takes is an independent decision that we reached looking at an overall assessment of the impact of the deal on competition, and we think that is the right decision for the UK," she said.

She noted the U.S. Federal Trade Commission was also pressing for the deal to be blocked on competition grounds.

Microsoft said yesterday it would appeal, with "aggressive" support from Activision.

Appeals against CMA rulings are heard by the Competition Appeals Tribunal, which makes a judgment on the merits of the decision. It will not be an opportunity for Microsoft to submit new remedies.

(Reporting Paul Sandle, Muvija M and Alistair Smout; editing by Emelia Sithole-Matarise and Elaine Hardcastle)