The European Court of Justice has taken new steps today against "golden shares" invoked by the Dutch and Italian governments that give them special voting rights in companies.
It was the latest move in a battle over protectionism that has pitted the court and the European Commission against steps by France, Poland, Spain and others to keep companies outside their borders from taking over key domestic firms.
In Luxembourg, an adviser to the European Court of Justice said the Dutch government's special voting rights in freight and postal services firm TNT violated EU rules.
He also said its golden share in telecoms firm KPN was illegal, although that advice has been overtaken by a recent decision by the Dutch government to give up the stake.
In Brussels, the Commission announced plans to open an inquiry into Italy's decision to give itself a veto over any attempt to take over gas network Snam Rete Gas.
The Dutch government privatised its telephone and postal services company in 1998, splitting it into KPN and TPG, but retained veto authority over some decisions through golden shares.
TPG later became TNT in a move that united the group's activities under the brand name of its international express and logistics businesses.
The advocate general agreed that the Dutch government's powers "may make it more difficult to acquire shareholding in the companies and are liable to deter investors from other member states from making such investments".
He said those special powers may restrict effective participation in the management or control of the companies and amount to an impediment to the free movement of capital, in violation of the treaties covering the 25-nation bloc.
Advice of advocates general is followed more than half the time by the European Court of Justice.
"We have no specific reaction as yet other than to say our services are going to investigate the situation there [in Italy]", said a commission spokesman for internal markets.
On Tuesday, the commission opened legal proceedings against Portugal over its golden share stake in Portugal Telecom.