A federal judge has issued a preliminary injunction blocking television giant Nexstar Media Group's proposed acquisition of rival broadcaster Tegna Inc. until an antitrust lawsuit can be resolved at trial.

U.S. Judge Trevor Nunley ruled that consumers could suffer irreparable harm if Nexstar was allowed to integrate Tegna's stations into its operations before the antitrust case is decided. The judge indicated the merger would likely violate the Clayton Act, the federal antitrust law governing corporate mergers.

The proposed deal, which had received approval from the Federal Communications Commission, would create a media company controlling 265 television stations across 44 states and Washington, D.C. This would significantly expand Nexstar's already substantial footprint in local television markets nationwide.

The preliminary injunction prevents the companies from moving forward with the integration while the underlying antitrust lawsuit proceeds through the courts. The ruling represents a significant obstacle to what would be one of the largest consolidations in the television broadcasting industry in recent years.

The merger has faced scrutiny from antitrust regulators and consumer advocates who have raised concerns about media consolidation and its potential impact on local news coverage and advertising markets. The case will now proceed to trial, where a court will make a final determination on whether the acquisition can proceed.