Margrethe Vestager, who heads competition policy in Europe, said her initial position is that Apple does not allow complete steering.

"Steering is important to ensure that app developers are less dependent on gatekeepers app stores and consumers are exposed to better offers," he said in a statement.

EU regulators said they are concerned because Apple's new business model makes it much harder for app developers to operate as an alternative marketplace and reach their end users on iOS.

"We will look at Apple's new business model – Apple imposes commercial conditions on app developers who want to reach end users on the iOS platform," the regulators said.

Regulators also said they had adopted their first preliminary findings into the non-compliance case.

“And this is about Apple again. About the many ways the new rules fall short of DMA requirements with regard to driving users to alternatives outside the Apple App Store. As they stand, we think that these new terms do not allow app developers to freely communicate with their end users and conclude contracts with them,” he said.