(Bloomberg)—Japan's worst earthquake on record may hurt the production of “thousands of companies” in Germany for several months, insurance broker Marsh & McLennan Cos. Inc. said.

“The most affected industries will be high-tech, steel and automotive,” Jochen Koerner, a member of the executive board of Marsh in Germany and Austria, said in an interview. “It could take a while until Japan has rebuilt its export infrastructure, and as a result there will be serious supply-chain problems for several months.”

The earthquake that hit Japan on March 11 may cause total economic losses of $200 billion to $300 billion, with most of the costs uninsured, catastrophe modeling firm Risk Management Solutions Inc. said on March 21. The estimate includes damage from the subsequent tsunami and the cost of evacuations, power disruptions and business interruption, RMS said, adding that insurance will cover “only a minor proportion” of the losses.

Catastrophe modeling firm EQECAT said on March 16 that insurers and reinsurers will probably have losses of $12 billion to $25 billion from the Japan earthquake and tsunami. Modeler AIR Worldwide had estimated insured losses of as much as 2.8 trillion yen ($35 billion) from the quake alone.

Contingency cover

“Most companies have basic business-interruption insurance, but less of them have an all-risk cover and even less have a contingency cover that also includes problems at suppliers,” Mr. Koerner said. “Normal business interruption only covers production stoppages at a company’s own facilities.”

Business-interruption insurance, which is sold by units of commercial insurers such as Allianz S.E., American International Group Inc. and Talanx A.G., protects business owners against lost earnings following catastrophes such as fire, flood or earthquakes. Coverage, which depends on the specific contract’s terms, may also include direct or even indirect supply-chain problems via so-called contingency coverage.

The Bank of Japan said last week the disaster may hurt business and consumer sentiment and prompt companies to cut factory output. Japanese companies such as Sony Corp. and Toyota Motor Corp. shut plants and extended production halts after the earthquake and tsunami. The disruptions may impede growth in the world’s third-largest economy, which was showing signs of emerging from a fourth-quarter slump before the temblor.

It may take months until the scope of insurers’ business- interruption claims from Japan can be estimated, Mr. Koerner said.

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