Enlarge / Despite Microsoft’s assurances, the CMA worries that making Call of Duty an exclusive would be in the company’s financial interests. (credit: Getty Images | Bloomberg)

The UK’s Competition and Markets Authority (CMA) came down squarely against Microsoft’s proposed $69 billion acquisition of Activision Wednesday morning. In a sprawling provisional report summary, the government regulator said the merger could hurt consumers by “weakening the important rivalry between Xbox and PlayStation gaming consoles” and “could result in higher prices, fewer choices, or less innovation for UK gamers.”

The CMA’s provisional findings focus on cloud gaming, where the CMA says Microsoft already accounts for 60 to 70 percent of the global market. After the merger, Microsoft would “find it commercially beneficial to make Activision’s games exclusive to its own cloud gaming service (or only available on other services under materially worse conditions),” the CMA said.

The CMA also expressed particular worry about “a small number of key games, including Call of Duty” being potentially locked to the Xbox and Windows PCs. While Microsoft has repeatedly promised that Call of Duty would remain fully available on other platforms for at least 10 years after the merger, the CMA notes that Microsoft has previously purchased other game studios and then “[made] their content exclusive to Microsoft’s platforms.”