November 26, 2014 - Discover has filed a lawsuit accusing rival card scheme Visa of anti-competitve practices in its debit card business.

Discover, through its Pulse Network unit, is challenging a Visa rule that requires issuers to use its PIN services rather than those provided by alternative networks, alleging that Visa is engaged in "illegal behavior to fend off competitive threats to its debit network services monopoly".

Discover contends that Visa is offering incentives to merchants to route their debit transactions solely over the Visa network, in defiance of a 2010 ruling that allows merchants to choose between one of any two processing networks for their debit transactions.

The suit states: "In order to maintain its monopoly, Visa has undertaken a series of illegal actions that undermine competition - harming rival debit networks, merchants, acquirers, card issuers, and consumers."

Visa has yet to respond to the allegations.