Microsoft’s $68.7bn (£55bn) deal to buy video game company Activision Blizzard has been blocked in the UK by the Competition and Markets Authority, the BBC reports.
The proposed takeover would see Microsoft acquire such hit titles as Call of Duty and Candy Crush.
But the regulator said it was concerned the deal would offer reduced innovation and less choice for gamers in the fast-growing cloud gaming business.
Microsoft and Activision hit out at the decision and said they would appeal.
“The CMA’s report contradicts the ambitions of the UK to become an attractive country to build technology businesses,” a spokesperson for Activision Blizzard said.