Visa Inc. deserted its $5.3 billion planned acquisition of financial-technology firm Plaid Inc. amid a Justice Department antitrust lawsuit that challenged the deal.The department sued to stop the deal in November, alleging the acquisition would let Visa unlawfully manage a monopoly in the online debit-card market. Plaid, the government argued, was an important competitive threat to Visa, and eliminating that threat would lead to higher prices, less innovation and higher entry barriers for online debit services.Visa initially pledged to fight the government, and a trial was scheduled for June in California federal court. Visa and Plaid mutually agreed to close the deal.Al Kelly, Visa’s chairman and chief executive, stated that he assumed the companies would eventually have won a legal battle due to Plaid’s services complimenting Visa’s. “However, it has been an entire year since we first announced our intent to acquire Plaid, and protracted and complex litigation will possibly take substantial time to fully resolve,” he said.