U.S. Justice Department investigates Visa over debit-card practices

The U.S. Department of Justice is investigating the involvement of Visa Inc’s anti-competitive practices in the debit-card market.

Visa did not immediately respond to the probe.

The department’s antitrust division has been gathering information on whether Visa, the largest U.S. card network, has limited merchants’ ability to route debit-card transactions over card networks.

Debit-card transactions are often less expensive, the people said.

Many of the department’s questions have focused on online debit-card transactions, but investigators have asked about in-store issues as well, the people said.

The probe highlights the important role of the so-called network fees that are invisible to consumers, lucrative for card companies, but a weight on merchants.