Last December they filed a complaint in a federal court in California, arguing that the $69 billion deal could substantially lessen competition or create a monopoly in violation of the Clayton Act.
The private anti-trust action, which was brought by 10 video game players in California, New Mexico and New Jersey, was dismissed in March after US District Judge Jacqueline Scott Corley found it failed to present sufficient evidence to support their claims.
However, the plaintiffs were given 20 days to refine their legal challenge and have now filed an amended lawsuit containing redacted information from Microsoft, including a strategy memo, and new information from the deal’s chief opponent, Sony Interactive Entertainment.
A Microsoft spokesperson told Reuters the amended complaint contained “unsupported and implausible claims about the deal’s effect on competition” and that the acquisition would “bring more games to more people”.
In December, the US Federal Trade Commission announced it was suing in a bid to block Microsoft’s proposed acquisition of Activision Blizzard over antitrust concerns.
UK regulator the Competition and Markets Authority is due to rule on the deal by April 26, while the European Commission will publish its verdict by May 22.