BRUSSELS (AP) — The European Commission has fined Mastercard 570 million euros ($648 million) for stopping retailers from looking for better card payment terms at banks around Europe.

The Commission, which polices competition, said Tuesday that Mastercard's rules prior to 2015 forced retailers to pay certain bank fees in the country they are located rather than let them shop around.

EU Competition Commissioner Margrethe Vestager said that "Mastercard's rules artificially raised the costs of card payments, harming consumers and retailers in the EU."

Mastercard, which also controls the Maestro brand, is the second-largest card program in Europe.

The Commission says the size of the fine was based on factors like the value of sales relating to the infringement and its gravity.

Mastercard was granted a 10 percent reduction for cooperating with investigators.