AXA SA said it sold catastrophe bonds designed to protect insurers from payouts on storm damage, in the biggest transaction of the notes in euros.

Europe’s second-largest insurer by market value issued 350 million euros ($474 million) of notes to institutional investors in two offerings through Calypso Capital II Ltd., it said in a statement. The bonds protect against extreme windstorm risk in 11 European countries from the U.K to Belgium.

“This issuance confirms AXA’s strategy to diversify the group’s cover against natural catastrophes, by both traditional reinsurance and alternative risk transfer such as catastrophe bonds,” Philippe Derieux, deputy chief executive of AXA Global Property and Casualty, said in a statement.

Paris-based AXA’s deal takes sales of catastrophe bonds in the common currency to 630 million euros this year, up from 230 million euros in 2012, according to data compiled by Bloomberg.

“We are seeing more and more insurers looking at insurance-linked investments, such as cat bonds, to replace part of their traditional reinsurance programs,” said Christian Bruns, who co-manages about $2.5 billion in insurance-linked strategies at Zurich-based LGT Capital Management Ltd.

The bonds are less risky than traditional re-insurance products because they are backed by collateral such as government securities, Bruns said.

AXA paid 290 basis points more than the three-month euro interbank offered rate on notes due in January 2018, according to the company’s statement. That compares with a spread of 410 basis points AXA paid to sell similar three-year securities in 2011, Bloomberg data show.

French insurer Groupama SA previously held the record for the largest euro-denominated catastrophe bonds, selling 280 million euros of the securities through Green Fields II Capital Ltd. in July, Bloomberg data show.

–Editors: Michael Shanahan, Jennifer Joan Lee