Marsh is warning of extended disruption to global business supply chains following Japan’s earthquake and tsunami.

While a lot of manufacturing plants were not badly damaged in the earthquake, the collapse of the country’s major power generation plant is leading to the shutdown of Japanese plants.

These are expected to in turn lead to business interruption insurance claims from many companies around the world which rely on Japanese components or goods.

Marsh Risk Consulting Head of Supply Chain Risk Gary Lynch says thousands of multinational companies rely on Japanese manufacturers for goods and services and the disruption will create significant global supply chain disruptions lasting for several months.

“Given that the immediate priorities in Japan are likely to be social not economic, the aftershocks to the global economies from this disaster may unfold very slowly,” he said. “Many of the economic consequences have yet to be seen.

“Rather than the physical destruction of the production facilities, most of the supply chain disruption from this catastrophe is likely to be caused by issues associated with infrastructure, energy, utilities, transportation, and restrictions on highway/port access.”

Mr Lynch says the industries most impacted will be the steel and car industries, as well as medical devices, shipbuilding and consumer electronics.

ON Semiconductor has shut down two plants in Japan due to disruption to electricity, fuel, gas, water and chemicals supplies being disrupted, it said in a statement.

The company is working with its insurance carriers to assess and recover incurred losses from business interruption, supply chain disruption and property damage.

The main Japanese car manufacturers – Toyota, Honda and Nissan – have all shut down production although Toyota is starting parts manufacturing later this week to keep its overseas plants operating.

But the shortage of automotive parts is already beginning to bite in the US, with General Motors temporarily shutting down a light truck manufacturing plant.