Visa shares are lower in premarket trading in New York after a Bloomberg report revealed that the US Justice Department is preparing to file a lawsuit against the world's largest payment network operator as soon as Tuesday. 

Unnamed sources in the report said the DoJ's antitrust division is expected to file the lawsuit in federal court today. The government prosecutors allege Visa participated in a range of anticompetitive conduct.

Antitrust enforcers are preparing to accuse Visa of taking steps to keep rivals from challenging its dominance in the debit card market, said the people. The government's allegations include that Visa made exclusive agreements to hinder the expansion of competing networks and thwarted efforts by technology companies to enter the market. -BBG

In July of 2023, Bloomberg reported that Visa was under scrutiny by the DoJ via a civil investigative demand that unleashed a probe into the payment processor's practices. This included "further civil investigative demands seeking additional documents and information focusing on U.S. debit and competition with other payment methods and networks," Visa wrote in a Form 10-Q.

DOJ's antitrust lawyers are likely focusing on Visa's practices and dominance in specific payment areas.

Visa shares are down 2% in premarket trading. Shares are near all-time highs. 

Last year, Visa's rival Mastercard faced similar antitrust investigations, with the Federal Trade Commission ordering the payment network operator to stop blocking competing debt payment networks.