Microsoft argued there had been a number of relevant developments since the UK Competition and Markets Authority (CMA) signalled its intent to block a proposed acquisition of Activision Blizzard, as it seeks to get the decision reversed.

In a response to the CMA’s final report notice, Microsoft highlighted a number of factors it believes constitute a material change in circumstance and so-called special reasons for the regulator not to adopt the blocking order.

Among the arguments, Microsoft pointed to the European Commission’s acceptance of its commitments in clearing the deal and a long-term agreement with Sony over distribution of Activision Blizzard game franchise Call of Duty.

Microsoft also claimed “significant” new material had emerged which “undermines” the CMA report conclusions in evidence from a similar case in the US looking into competition implications of the proposed acquisition.

The CMA opened Microsoft’s latest submission for comments, noting this process was “not a usual part of the CMA’s process during a remedies implementation”.

“However, in light of the guidance provided by the Competition Appeal Tribunal on this specific case, the Inquiry Group has decided it is appropriate to do so in this case,” it added.

The deadline for comments on the Microsoft document is 4 August. The authority noted it was especially interested in whether there had been material change of circumstance since its original decision.