The nation's five major nonlife insurance firms made public for the first time on Friday their solvency margin ratios -- a benchmark for their exposure to risk -- as part of new guidelines to better disclose information on operations.

The figures reflect the insurer's degree of solvency in view of the total amount of potential risk. The total solvency margin at a nonlife insurer includes such resources as its capital, funds, various provisions and reserves, and a portion of its latent profits on land and stock holdings.

According to the figures released, the ratio for Tokio Marine & Fire Insurance Co. stood at 1,750 percent as of the end of March, while that for Yasuda Fire & Marine Insurance Co. was 961.9 percent. Mitsui Marine & Fire Insurance Co. said its ratio was 1,001.9 percent, and Sumitomo Fire & Marine Insurance Co. and Nippon Fire & Marine Insurance Co. calculated ratios of 1,057.7 percent and 1,004.4 percent, respectively.

The ratio is expected to be a key measure for regulators when a system of prompt corrective action to check insurers' corporate health against against objective criteria is introduced this fiscal year.