The EU has become the latest regulatory body to take formal steps in an attempt to scupper Microsoft’s planned acquisition of Activision Blizzard, issuing the Xbox giant with a formal warning regarding the deal, reports Politico.

At $69 billion, the proposed deal would be the biggest acquisition in gaming history, however it has come under significant criticism from regulatory bodies worldwide due to how it could affect competitors. The Call of Duty franchise has been cited as a major factor, with PlayStation boss Jim Ryan reportedly lobbying against the deal which could make the franchise an Xbox exclusive. Countering such claims Microsoft have long maintained that the prime reason for the acquisition is Activision Blizzard’s strength on mobile platforms.

However, this tack brings problems of its own, with Google last month raising its own opposition, claiming that Microsoft’s plans to open its own mobile game store could see games developed by Activision Blizzard subsidiary King taken off of competing app stores.

Unfriendly competition

The European Commission’s antitrust enforces detailed there concerns regarding the deal in a statement of objections sent to Microsoft on Tuesday. While exact details are unknown, the commission has previously stated that the deal would need to be investigated thoroughly due to the possibility that it could adversely affect competitors.

Microsoft has signalled its intention to finding a path forward for the deal, with a spokesperson for the company stating “we are listening carefully to the European Commission’s concerns and are confident that we can address them.”

Microsoft has previously attempted to assuage concerns regarding the deal, including offering Playstation a three year extension on its current deal with Activision Blizzard, which Jim Ryan told Gamesindustry.biz was “inadequate on many levels.” However, the company is seemingly prepared to make more serious concessions, including offering to sign a legally binding consent decree confirming its intent to keep Call of Duty available on competing platforms.

The  EU's investigation into the deal began in November, with a final dealine of March 23.

We listed Activision Blizzard as one of the top 50 mobile game makers of 2022.