NEW YORK (AP) — Another earthquake that shook the northernsection of Japan rattled the stocks of insurance and reinsurancecompanies on Thursday.

The magnitude-7.4 aftershock knocked out power across a largeportion of the area that was devastated by the March 11 earthquakeand tsunami, which killed about 25,000 people, tore apart entirecommunities and triggered an ongoing crisis at a nuclear powerplant.

A new tsunami warning was issued following the aftershock, butcancelled about 90 minutes later.

In the minutes after word of the latest quake spread, insuranceand reinsurance companies with exposure to the area saw stocksdive. As it became clear that there was no heavy damage, sharesmainly recovered.

Still, the first three months of this year “will go down in therecord books as among the worst in global underwriting history,”analysts at Keefe, Bruyette & Woods said in a note to clientsissued earlier Thursday.

The Japan quake and tsunami, coming on top of the Feb. 21earthquake in New Zealand and earlier flooding in Australia, has resulted in tensof millions of dollars of losses for the industry. The Japan quakealone is likely to be one of the costliest catastrophes in history— industry loss estimates climb as high as $25 billion to $30billion.

KBW warned that another major event could pressure capitalreserves for some companies. It noted that the industry has beenunable to pin down loss estimates, and the nuclear crisis makesassessment even harder than usual after a disaster.

However, it is widely expected prices will rise as companies reassess their coverage. That belief sent thesector's stocks up earlier in the week, with many companiesreaching new highs.

Among the hardest-hit stocks in the group Thursday was AmericanSafety Insurance Holdings Ltd. The Hamilton, Bermuda-basedreinsurance company, which estimated it would record up to $7million in losses for the first quarter without counting Japan, sawshares fall $1.09, or 5.1 percent, to $20.38 in afternoontrading.

Also down was ACE Limited, a reinsurance company based inZurich. Shares fell 63 cents to $65.85 in afternoon trading.

Everest Re Group Ltd., another Bermuda reinsurer, also dipped.The company said its initial estimate saw losses in New Zealand ataround $180 million and in Australia, around $45 million. Itexpects “significant” losses in Japan but has not yet released anestimate. Shares gave up 31 cents to $93.45.

PartnerRe Ltd. has said it expects to pay out up to $240 millionfor the New Zealand quake but has not yet offered estimates forJapan. Shares of the Pembroke, Bermuda-based reinsurer slipped 28cents, to $82.24.

Shares of RenaissanceRe Holdings Ltd., also based in Bermuda,slipped 26 cents, to $71.46. It has put its total losses forAustralia and New Zealand at about $220 million, and said Japanlosses are likely to be “material.”