The European Commission (EC) on Wednesday opened three in-depth investigations on corporate taxation of Apple, Starbucks and Fiat by some EU member states.

The EC will examine whether decisions by Ireland, the Netherlands and Luxembourg with regard to the corporate income tax of the three companies are in line with EU state aid rules, an EU statement said.

Joaquin Almunia, Vice President of the European Commission responsible for competition policy said: "We have reasons to believe at this stage that in these specific cases the national tax authorities have renounced to tax part of these multinationals' revenues by allowing them to lower their taxable profits."

These investigations are related to the so-called "tax rulings" with Apple in Ireland, Starbucks in the Netherlands, and Fiat Finance and Trade in Luxembourg.

"It is well known that some multinationals are using tax planning strategies to reduce their global tax burden. These aggressive tax planning practices erode the tax bases in our Member States," Almunia said.

It will "seriously distort competition in the EU Single Market," he said, adding that "it cannot be accepted that large multinationals do not pay their fair share of taxes."