British regulators blocked Microsoft’s $69 billion purchase of video game maker Activision Blizzard on Wednesday, saying it would hurt competition in the cloud gaming market.

In its final report, the Competition and Markets Authority said, "the only effective remedy" to the substantial loss of competition "is to prohibit the merger" of what would be the largest deal in tech history.

Both Microsoft and Activision will appeal the decision, despite facing opposition to the all-cash deal from contemporaries like Sony and regulators in the U.S. and Europe concerned the consolidation would give Microsoft control of popular game franchises like Call of Duty, World of Warcraft and Candy Crush.

Microsoft President Brad Smith said in a tweet Wednesday that the company remains fully committed to the acquisition and would appeal the decision.

"The CMA's decision rejects a pragmatic path to address competition concerns and discourages technology innovation and investment in the United Kingdom," he continued. "We have already signed contracts with Activision Blizzard’s popular games available on 150 million more devices."

Cloud gaming enables the streaming of games to tablets, phones and other devices, freeing gamers from buying expensive consoles and gaming computers.

In an interview with FOX Business in February, Activision Blizzard CEO Bobby Kotick credited the company's expansion into 190 countries to the smartphone.

"I don't think we would have ever expected more games played on Apple iPhones and Android phones," he said. "What used to be a business about middle-class consumers in developed countries has now expanded."