The Federal Trade Commission is set to file for an injunction Monday seeking to block Microsoft's proposed acquisition of Activision Blizzard, a person familiar with the matter told CNBC.
By filing for an injunction, the FTC is seeking to stop the transaction from going through before the deal's July 18 deadline.
The FTC had already sued to block the $68.7 billion acquisition, choosing to bring the case before its internal administrative law judge. Through that trial-like process, the judge would make an initial decision that could be appealed to the full commission for a vote. After that, Microsoft could appeal to a federal court should the decision not go its way. The case is set to go before the administrative law judge in August.
An appeal of the U.K.'s Competition and Markets Authority's decision to block the merger is also scheduled to take place this summer shortly after the acquisition deadline.
"We welcome the opportunity to present our case in federal court," Microsoft President Brad Smith said. "We believe accelerating the legal process in the U.S will ultimately bring more choice and competition to the market."
Shares of Microsoft and Activision were roughly flat Monday afternoon.
WATCH: What the blockbuster Microsoft and Sony deals mean for the future of gaming
