Japanese reinsurance contracts up for renewal April 1 had “relatively orderly price movements,” but if reinsurers are tested again this year with one more major event, the global market is more likely to change, according to reinsurance broker Willis Re.

In addition to the devastating earthquake in Japan this month, 2011 already has seen floods and Cyclone Yasi in Australia, and an earthquake in New Zealand. The reinsurance broking arm of London-based Willis Group Holdings P.L.C. estimated that insurers suffered $60 billion in losses globally during the 13-month period ending March 2011, and passed $35 billion to $42 billion of those losses on to their reinsurers. Many of the losses reinsurers suffered have “largely exhausted” their annual catastrophe loss budgets, Willis Re said in a report.

Reinsurers are coping with that challenge by increasing the rates they charge to insurers in some areas. For example, the property excess-of-loss rates for natural catastrophes increased internationally between 5% and 50% for April 1 renewals, compared with a year ago. In Japan, rates on property excess of loss coverage related to earthquakes rose between 20% and 50% April 1.

While some buyers in Japan renewed their contracts for the year starting April 1 with rate increases, others extended their coverage for up to 3 months to allow pricing negotiations to be conducted when the loss situation becomes clearer, Willis said.

Other forms of reinsurance in Japan stayed the same. For example, excess-of-loss coverage for property damages excluding earthquakes renewed April 1 in the country at unchanged rates compared to last year, Willis said.

“While the financial strength of the reinsurance industry remains remarkably intact in the wake of Tohoku, it can only withstand so many blows,” said Peter Hearn, chairman of Willis Re, in a statement. He said it might take only one more major event to make the market turn and prices rise. “It could be something as dramatic as a catastrophic hurricane during the upcoming North Atlantic and European winter windstorm seasons or something more systemic like creeping inflation, but whatever the cause, reinsurers have proven their resilience and are gearing up for a bumpy ride over the remaining months of 2011.”