Germany's Munich Re warned it could miss its profit target this year, the first major reinsurer to flag a hit to earnings from damage caused by hurricanes Harvey and Irma.
"These two events are expected to result in high insured losses, which the market and Munich Re are unable to quantify at the moment," it said in a statement.
Analysts said they expected this to be the first of a series of such statements as insurers count the costs of the destructive storms.
Irma, one of the most powerful Atlantic Ocean storms on record, ravaged several islands in the northern Caribbean, killing at least 60 people, before barrelling into Florida's Gulf Coast on Sunday, causing further destruction.
Munich Re had earlier this week estimated losses for the global insurance industry from Harvey, which struck Texas two weeks ago and caused massive flooding, of between $20 billion and $30 billion.
It put the storm on the scale of Hurricane Sandy in 2012.
Munich Re said it would probably report a third-quarter loss due to the hurricanes, but that it had a sufficiently solid capital base to still be able to offer full reinsurance capacity to its clients.
It said it may miss its full-year net profit goal of €2-2.4 billion). Analysts on average have forecast €2.35 billion, according to Thomson Reuters data.
Munich Re had said as recently as Sunday, at an annual industry meeting in Monte Carlo, that it was not especially exposed to Florida.
Analysts said Munich Re had an advantage over peers such as Swiss Re, given it had one of the largest budgets in the industry to cover natural catastrophes, at €1.4 billion for the full year.