A judge has granted a request by US regulators to temporarily block Microsoft’s $69bn (£56bn) takeover of Activision Blizzard.
The court says the temporary restraining order “is necessary to maintain the status quo while the complaint is pending”.
The US Federal Trade Commission (FTC) says the deal could “substantially lessen competition” in the sector.
A two-day hearing is now due to take place from 22 June in San Francisco.
The deal to buy Activision Blizzard – the company behind Call of Duty and Candy Crush – would be the biggest in the history of the video games industry.
It has split competition regulators in the UK, US and Europe. The UK has blocked buyout while the European Union approved it. In order for the deal to go through, Microsoft and Activision need approval from regulators in the UK, the EU and the US.
The FTC has argued that the deal would give Microsoft’s Xbox console exclusive access to Activision games, leaving competitors Nintendo and Sony out in the cold.
Microsoft and Activision now have until 16 June to submit legal arguments to oppose the preliminary injunction and the FTC will have to reply on 20 June.
Microsoft has said a takeover of Activision would benefit gaming companies and players.
It has offered to sign a legally binding agreement with the FTC to provide Call of Duty games to rivals including Sony for a decade.