It marks one of the first probes by a major antitrust enforcer into the $68.7 billion deal, which was announced in January.
In a statement, the U.K.’s Competition and Markets Authority said its investigation would “consider whether the deal could harm competition and lead to worse outcomes for consumers – for example, through higher prices, lower quality, or reduced choice.”
The CMA has set a Sept. 1 deadline for its initial decision. The regulator said it wants feedback from interested third parties, with a consultation running until Jul. 20, 2022.
Microsoft was not immediately available for comment when contacted by CNBC.
The acquisition has huge implications for the $190 billion video game industry, handing control of incredibly lucrative franchises including Call of Duty, Candy Crush and Warcraft to one of the world’s biggest tech companies.
Microsoft hopes the purchase will help it in the race to build the so-called “metaverse,” a hypothetical network of large virtual worlds. Various other companies are vying for a role in the space, including Facebook parent company Meta and Sony.
However, analysts are skeptical about the chances of a deal being approved by regulators.
Microsoft is one of the largest games console manufacturers alongside Sony and Nintendo, and the company is sitting on a growing hoard of first-party content — including popular game series like The Elder Scrolls and Doom, which it acquired after buying Bethesda-owner Zenimax for $7.5 billion.
Meanwhile, Activision has been beset by numerous internal issues in the past year, including accusations of sexual harassment, unionization efforts and walkouts from staff.
Employees at the company are deeply unhappy with the management and have called on CEO Bobby Kotick to resign. Microsoft previously said Kotick will stay on as CEO of Activision until after the deal closes.