STORY: The U.S. is set to sue Visa over allegations it monopolised the country's debit card market.

That's according to a report by Bloomberg, which says court action could come as soon as Tuesday (September 24).

The Department of Justice is reportedly preparing to accuse Visa of taking steps to prevent competitors challenging its dominance.

There was no immediate comment on the report from the department or the company.

Last year, the DOJ issued an investigative demand to Visa, seeking information about its debit card operations.

The probe was initiated back in 2021, at which time the firm said it complied with all relevant laws.

Earlier this year, Discover Financial Services settled a suit in Texas, in which it accused Visa of obstructing competition in debit services, and causing merchants to pay higher fees.

Rival Mastercard has previously faced similar allegations regarding its U.S. debit operations.