"Ongoing remedial measures" helped steady the insurer's performance after natural catastrophe and large loss events caused volatility, the ratings agency said.
The Hong Kong subsidiary swung back to profit in 2024, with the ratings agency also pointing to the importance of its cross-border role linking mainland China and Hong Kong.
The Bangkok-based non-life reinsurer earns an aa+.TH national scale rating, though AM Best flagged exposure to heightened credit and liquidity risks from holdings in a sanctioned country.
Overseas premiums are projected to account for about 50% of non-life premiums and profits in FYE26, supported by its US$3.5bn acquisition of Aspen Insurance.