Updated

The European Union Commission's antitrust regulator is investigating deals that Apple, Starbucks and Fiat struck with tax authorities in several European countries to see whether they amount to unfair state aid.

The multinationals have agreements with tax authorities in Ireland, the Netherlands and Luxembourg as part of their strategy to minimize the taxes they pay. The EU antitrust commissioner, Joaquin Almunia, said Wednesday that while such agreements are permissible in theory, they would be improper if they give the companies involved an advantage over competitors.

The companies named have been frequent targets of criticism for paying low taxes in some places they operate.

The countries have also been criticized — Ireland for its low tax rates, the Netherlands and Luxembourg as homes for shell companies, and all three for secrecy.