The country's six biggest nonlife insurers announced Thursday large year-on-year increases in their after-tax profits for the April-September period partly due to the smaller-than-usual incidence of natural disasters.

However, according to the companies' consolidated earnings reports for the April-September period released Thursday, with the exception of Tokio Marine Holdings, Inc., all the companies suffered a year-on-year decline in their net premiums -- a figure that corresponds to the sales figures of other companies.

In the case of Tokio Marine Holdings, good performances in its overseas acquisitions led to an increase in premiums.

The other five insurers are Aioi Insurance Co., Mitsui Sumitomo Insurance Group Holdings, Inc., Nipponkoa Insurance Co., Nissay Dowa General Insurance Co. and Sompo Japan Insurance Inc.

As the nonlife insurance industry is set to realign itself into three major groups next spring, it is expected that many insurers will raise their insurance premiums to enhance their earnings strength.

The increase in the companies' after-tax profits was strongly linked to temporary factors such as the smaller-than-expected number of typhoons this year and the recovery of share prices, which helped firms stabilize their asset management. But their consolidated net premiums were strongly affected by the economic downturn.

As for auto insurance sales -- the core product for nonlife insurers -- all the companies apart from Nissay Dowa reported a year-on-year decline in income due to slumping auto sales and a cut in the compulsory automobile insurance premium.

All six companies also reported significant falls in the premiums they received for their marine insurance products because of plunging demand for shipping due to the global economic crisis.

As reference rates used by nonlife insurers to decide their auto insurance premiums were raised this summer, likely these nonlife insurers will raise their insurance premiums in the near future.

Meanwhile, after announcing their earnings results, Sompo Japan and Nipponkoa said they had been working hard to gain approval for the planned management integration. Both companies will hold extraordinary shareholder meetings in December over the alliance, but U.S. investment advisory firm Southeastern Asset Management, which holds large stakes in both firms, has expressed doubts over the deal.

"We've been trying to gain the understanding [of Southeastern Asset Management] for our plans for corporate governance of our envisaged management setup and our approach to asset management," Sompo Japan Managing Executive Officer Hiroyuki Yamaguchi said at the earnings report press conference.

"We'll explain [to Southeastern Asset Management] in a way that should gain its understanding," Yasuhide Fujii, Nipponkoa managing executive officer, said at another press conference.