The main driver of the high insured losses was an active hurricane season in the North Atlantic. In addition, the combined insurance losses from all wildfires worldwide were $14 billion, the highest ever in a single year.
A deal would see Japan's third richest-man follow other business titans such as Warren Buffett in seeking to profit from the cash flows provided by reinsurance.
The deadliest mass shooting in modern U.S. history is adding to soaring costs for insurance companies, which are already taking a beating this year from an onslaught of hurricanes, earthquakes and wildfires.
The storm shifted to Floridas Gulf Coast over the weekend, sparing Miami a direct hit and prompting risk modeler AIR Worldwide to say the maximum cost for insurers on Irma is $40 billion.