July 11 - The European Commission (EC) has opened an "in-depth" investigation into tax exemptions granted to five Netherlands based ports, to verify that they are in line with European Union state aid rules.

The ports in question include Rotterdam, Amsterdam, Zeeland, Groningen and Moerdijk. The EC will look into whether corporate tax exemptions granted to these publically-owned organisations breach European Union competition rules by giving them an unfair advantage in the market.

Commission vice president in charge of competition policy, Joaquín Almunia, said: "Fair competition is crucial for all market players. The Commission therefore needs to verify that public companies, including port operators, in the Netherlands are not given more favourable tax treatment than their private competitors.

"Furthermore, there should be a level-playing field between ports in the EU, so it is important to make sure that state aid rules are being complied with in all Member States."

The EC has issued letters to Belgium and France to ensure they too are operating within EU state rules, and has requested further information from the German government on its port taxation system.

In May 2013, The EC encouraged the Dutch government to abolish corporate tax exemptions for public companies. While the Netherlands adhered to the request, it kept the tax breaks in place for the five ports now under investigation.

Further information on the proceedings can be viewed on the EC website here.