A FAULT in the German power grid plunged millions of people into darkness across Western Europe and provided a reminder of the fragility of the Continent’s energy supply as it heads into winter.

The power cut is believed to have been caused by technical problems with German power lines, which led to a chain reaction of energy shortfalls across Europe.

It happened just after 10pm on Saturday and lasted for up to 90 minutes in some areas, halting trains and affecting households from northern Germany to Morocco. E..On, the Germany utility company, which is one of the biggest in Europe, said that the problem may have arisen when it switched off a power line over the river Ems, in the north of the country, to allow a large ship to pass underneath safely.

A 380,000-volt line was turned off to let the Norwegian Pearl, a newly built cruise ship, pass on its way from the Meyer shipyard in Papenburg to the North Sea. The loss of power may have overstretched other power lines.

“Such switch-offs have been undertaken repeatedly in the past without any problems,” E.On said in a statement. “It is still unclear where and how the acute fault occurred half an hour after the switch-off. E.On is working flat out to obtain a detailed analysis.”

Sigmar Gabriel, the Environment Minister for Germany, said that the blackout showed that power companies urgently needed to expand their network capacity and replace old lines. “They need to invest their profits in the electricity network,” Herr Gabriel said.

“We need effective networks in the European power market.”

Romano Prodi, the Italian Prime Minister, said that the blackout indicated that Europe needed its own electricity supervisory authority.

“My first impression is that there is a contradiction between having European [power] links and not having one European [power] authority,” Signor Prodi said. “We depend on each other with being able to help each other, without a central authority.”

The power cut swept through large parts of western Germany, France, Belgium, Italy, Spain, Austria, the Netherlands and Croatia. About 100 trains in Germany were brought to a standstill, causing nationwide delays to the rail network.

In France, five million people were affected in the country’s biggest blackout in 30 years, according to a spokesman for the CGT trade union. Regions in the north of the country were affected, as were districts of Paris and Lyon.

Firefighters in Paris responded to nearly 40 calls from people stuck in lifts. More than 100,000 people were affected in Italy, mainly in and around Turin.

“We have a combined European grid. So a power failure can indeed have far-reaching consequences in several countries,” said Theo Horstmann, a spokesman for RWE Rhein-Ruhr, the German regional energy provider.

Pierre Bornard, management board member of RTE, the French power supplier, said that the sudden loss of power in Germany had thrown the power grid in Europe out of balance and caused computer systems to switch off power for some customers to prevent a complete blackout. He described it as a “house of cards” phenomenon.

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