The US Federal Trade Commission (FTC) asked a federal court on Monday to block Microsoft from completing its $69 billion buyout of gaming giant Activision Blizzard, a court filing showed. “A preliminary injunction is necessary to… prevent interim harm" while the FTC determines whether “the proposed acquisition violates US antitrust law," the regulator said in the filing. In requesting the preliminary injunction at the Northern California District Court, the US government sought to prevent the companies from finalizing the deal before a July 18 deadline. An FTC hearing is set for August to argue the merits of the deal, but…