Ninety per cent of insurers that reported results met the minimum capital requirements to withstand a shock such as a severe recession, the European Insurance and Occupational Pensions Authority said.
But it found that 13 firms would have too little capital as set out in new Solvency II rules and would need a further €4.4bn (£4bn) between them to meet the minimum level.
Another ten companies did not have the capital to cope with a scenario where rising inflation causes interest rates to rise rapidly.
EIOPA, which reports to the EU’s internal market and services commissioner Michel Barnier, said the sector “remains robust in the occurrence of major shocks”. But it said many firms were vulnerable to a downward spiral in sovereign bond markets.
The results covered 129 insurance and reinsurance groups from March and May.