The Norwegian Competition Authority has fined local grocery store chains, NorgesGruppen ASA, Rema 1000 International AS, and Coop Norge SA, a combined 4.9 billion Norwegian crowns ($466.3 million) for breaching antitrust regulations, Retail Insight Network reported citing Reuters. The authority said the three largest supermarket chains in the country of engaged in illegal collaboration that weakened competition, and likely higher prices.