The industry's damage claim is around $100 million for the plane, thought to have crashed on March 8 and lost all 239 people aboard after flying thousands of miles off course. Insurers so far have been reluctant to speculate about the size of other claims linked to the case.
Hiscox also took a loss from the ferry carrying 462 people that capsized off South Korea last month, in what could be the country's biggest maritime disaster in over 20 years.
The Lloyds of London insurer and reinsurer posted a marginal decline in quarterly gross written premiums to 501.6 million pounds ($846.1 million), blaming its planned step back from the reinsurance market where rates continued to decline.
Japanese earthquake rates fell by around 15 percent during the April 1 renewals. Rates in the U.S. catastrophe market, already hit by a lull in claims, continued to overreact to new capital, Hiscox said in a statement.
The absence of major hurricanes in the United States last year has led to a fall in catastrophe reinsurance rates, which has been exacerbated by the growing popularity of "catastrophe bonds" sold by insurers to share risk for natural disasters.
Hiscox shares lost early gains and were down 0.7 percent at 706.5 pence at 0708 GMT on the London Stock Exchange on Tuesday. ($1 = 0.5929 British pounds)