Profits at Japan's 11 major nonlife insurance companies plunged sharply in the fiscal first half to Sept. 30, due to falling share prices and large reserves set aside for claims related to the Sept. 11 terror attacks in the United States.

Combined payments related to the attacks reached 193 billion yen, according to the companies' business results, announced Tuesday.

As an industry realignment proceeds, the results illustrated the widening gap between the strong and weak, with four of the smallest slipping into the red on a pretax basis.

Tokio Marine & Fire Insurance Co., the biggest casualty insurer, said its parent-only pretax profit plunged 28.4 percent in the period as falling share prices forced it to book 21.17 billion yen in securities appraisal losses.

Unconsolidated pretax profit totaled 49.04 billion yen, compared with 68.49 billion yen a year earlier.

Net premium revenues -- the equivalent of sales at manufacturers -- rose 2.9 percent to 662.05 billion yen.

Its parent-only net profit inched up 0.4 percent to 32.16 billion yen.

Its solvency margin ratio stood at 1,240.2 percent as of Sept. 30, down from 1,278 percent as of March 31 but well above the 200 percent threshold for financial instability.

The solvency margin ratio is the most closely watched gauge of a insurer's financial health. It measures an insurer's ability to make good on policy obligations.

Mitsui Sumitomo Insurance Co., the nation's second-largest casualty insurer, reported that earnings dropped in the half-year period due largely to merger costs and securities appraisal losses.

Mitsui Sumitomo, born from the Oct. 1 merger of Sumitomo Marine & Fire Insurance Co. and Mitsui Marine & Fire Insurance Co., said it posted a combined pretax profit of 26.29 billion yen in the April-September period, down 2.2 percent from the same period the previous year.

Mitsui Sumitomo's combined net profit fell 25 percent to 13.81 billion yen, on a 2.7 percent rise in net premium revenues to 609.54 billion yen.

The main factor behind the decline was the 21.26 billion yen in appraisal losses in securities holdings, which plunged in value with the decline in Japanese share prices, the company said.

It also cited an extraordinary loss of 8.41 billion yen in merger-related costs and writeoffs for retirement and pension-related liabilities.

Net premium income grew largely due to brisk sales of automobile and fire insurance policies, the company said.

Yasuda Fire & Marine Insurance Co., Japan's third-largest casualty insurer, said it fell into the red in the fiscal first half ended Sept. 30 as falling share prices forced it to book 57.29 billion yen in securities appraisal losses.

It posted an unconsolidated pretax loss of 43.62 billion yen, a turnaround from a profit of 19.37 billion yen a year earlier. Its parent-only net loss amounted to 23.05 billion yen compared with a profit of 4.64 billion yen.

Net premium revenues edged up 2.6 percent to 481.17 billion yen.

Meanwhile, Nissan Fire & Marine Insurance Co., fell into the red after setting aside larger claim reserves for payments related to the Sept. 11 attacks.

The midsize nonlife insurer posted a parent-only net loss of 13.46 billion yen, reversing a profit of 2.54 billion yen a year earlier.

It also posted a parent pretax loss of 20.73 billion yen in a turnaround from a profit of 9.40 billion yen a year earlier on a 0.6 percent fall in net premium revenues to 130.70 billion yen.

Its solvency margin ratio as of Sept. 30 stood at 754.7 percent, down from 1,200.4 percent as of March 31.