The European Union has fined Apple over 1.8 billion euros for abusing its dominant market position to set unfair rules for developers of music-streaming apps.

The European Commission on Monday said the US tech giant bans developers from informing iPhone and iPad users of cheaper music subscription services available outside its App Store. It said Apple's restrictions amount to "unfair trading conditions."

It said Apple's move "may have led many iOS users to pay significantly higher prices for music streaming subscriptions because of the high commission fee imposed by Apple on developers."

The EU's competition commissioner, Margrethe Vestager, said the "illegal" action has impacted "millions of European consumers who were not able to make a free choice as to where, how and at what price to buy music streaming subscriptions."

Apple said it would contest the EU's decision. The firm said in a statement, "The decision was reached despite the Commission's failure to uncover any credible evidence of consumer harm."