The Federal Trade Commission on Thursday filed an antitrust case against Microsoft to challenge the software maker’s attempt to acquire video game publisher Activision Blizzard, claiming it would violate U.S. law.

This isn’t Microsoft’s first time dealing with competitive pressure. In 1998 the U.S. Justice Department filed a broad antitrust case against the company. Microsoft changed some practices related to its Windows operating system business as a result. Regulators in the United Kingdom are looking into whether the Activision Blizzard acquisition would lessen competition in the country.

Microsoft announced plans to acquire Activision Blizzard for $68.7 billion in January, with the goal of closing it by June 2023. The deal has come under pressure from Microsoft’s competitors in gaming, such as Sony. Microsoft has repeatedly said it won’t be the world’s leader in gaming if the deal were to close, and it has vowed to provide popular “Call of Duty” games on gaming platforms other than those owned by Microsoft.