The Federal Trade Commission plans to file in federal court to prevent Microsoft and Activision-Blizzard from closing their $69 billion merger, according to a person familiar with the matter.

The filing, which is not yet public, will ask the US District Court for the Northern District of California for a temporary restraining order that could keep the companies from consummating the acquisition while the FTC's in-house court is deliberating on the deal.

The FTC sued Microsoft in the agency's administrative court in December, challenging the deal as anticompetitive.

Microsoft didn't immediately respond to a request for comment.

UK competition regulators have also challenged the deal, which promises to make Microsoft the world's third-largest video game publisher after Tencent and Sony. The acquisition would give Microsoft control over popular franchises including "Call of Duty" and "World of Warcraft."

Officials from the FTC and the UK have claimed that the deal could harm the gaming industry by allowing Microsoft to withhold Activision titles from rival platforms, such as Sony's Playstation. Microsoft has struck 10-year licensing agreements with some game platforms that will ensure those titles remain available.

Antitrust officials from the European Union blessed the deal last month, saying that Microsoft's concessions were enough to address its competition concerns.