The UK's Office of Fair Trading is to investigate new interchange fees introduced by MasterCard in November that appear to infringe competition rules.
The UK competition watchdog says the new fee arrangements continue to be set with reference to 'extraneous costs' and used to recover such costs.
In September last year the OFT ruled that a collective agreement by banks over MasterCard's interchange fees infringed competition rules and led to higher retail prices. A similar ruling against Visa followed the next month. Both card associations are appealing the ruling.
The OFT says it will not reach any firm decision as to infringement relating to the new fee-setting arrangements until the appeal tribunal proceedings have been concluded.