Akhir 06 , 1432 H. / March 11, 2011 -- Shares in the world's leading reinsurance groups fell sharply Friday following Japan's devastating earthquake, according to dpa. As the trading day got underway, shares in Munich Re, Swiss Re and Hanover Re, the world's top three reinsurers had slumped by more than 4 per cent apiece. Reinsurers handle the risk of insurers. The Japanese earthquake and the tsunami that it triggered comes after a string of costly natural disasters for the global insurance business, which have included calamitous floods and a cyclone in northern Australia and a massive earthquake in the New Zealand city of Christchurch. Signs have already started to emerge of the financial pressures facing the insurance sector as a result of the series of catastrophes. On Wednesday, Munich Re announced a 39-per-cent drop in fourth- quarter profits, to 467 million euros (649.3 million dollars). The Munich-based group said full-year net profit declined 3.9 per cent to 2.42 billion euros, from 2.52 billion euros in 2009. Swiss Re said this month that the earthquake in New Zealand alone is likely to cost the group about 800 million dollars. Total claims for the insurance sector as a result of the New Zealand earthquake are likely to come in at between 6 billion and 12 billion dollars, Swiss Re said.