A closely watched supermarket merger challenge has ended with the proposed Kroger-Albertsons tie-up collapsing after courts sided with antitrust enforcers, marking one of the most significant recent victories for regulators policing consolidation in consumer-facing markets.

The $24.6 billion deal had drawn lawsuits from the Federal Trade Commission and state attorneys general, who argued the transaction would reduce competition for grocery shoppers and workers in hundreds of local markets.