The product provides protection against economic losses caused by navigation system disruption, including port-entry bans, vessel detention and delayed departures.
Reinsurance and cat bond cover will limit the earnings hit, but the agency said semiconductor-driven industry clusters could push net losses above 2016's.
Estimates from across the broker and ILS market point the same way, with losses expected to fall short of the quakes that struck the same prefecture a decade ago.
Strategic alliances with global asset managers are emerging as a preferred route for Japanese lifers seeking diversification and higher investment returns.