By Leika Kihara and Rie Ishiguro
TOKYO (Reuters) - Japan counted the financial cost on Monday of its worst catastrophe since World War Two as the economy shuddered, prompting the central bank to line up a record $183 billion in funds to stabilize the banking system.
Markets swooned at the shock of an 8.9 magnitude earthquake and a tsunami that may have killed more than 10,000 and has left millions of people without power, water or homes.
If that was not enough, engineers were battling to prevent a nuclear meltdown at the Fukushima Daiichi complex owned by Tokyo Electric Power Co (TEPCO), where three reactors were threatening to overheat in the worst atomic power accident since Chernobyl in 1986.
The insurance cost of the quake, which hammered the northeast coastline, could reach $35 billion even before the tsunami is accounted for, said risk modeling company AIR Worldwide. That is nearly as much as the entire worldwide catastrophe loss for the global insurance industry in 2010.
A swathe of top-name Japanese manufacturers, including Sony Corp, Toyota Motor Co and Panasonic have shuttered production lines, with restart efforts hampered by quake aftershocks.
About a fifth of the country's nuclear power generation capacity has been shut down by the disaster. Thermal plants also shutdown, forcing the world's third-biggest economy to instigate rolling blackouts to conserve energy.
"The economic consequences appear to be greater that we perhaps originally expected," said Tom Byrne, senior vice president at Moody's Investor Service.
Indeed, economists said that the triple blow of quake, tsunami and nuclear accident is set to damage the already struggling economy harder and longer that initially expected.
The analysts have grown increasingly cautious about forecasting a quick economic rebound similar to that after the Kobe earthquake in 1995. Some say a recession is possible.
"Power supply is a critical factor," said Michala Marcussen, head of global economics at Societe Generale. "If power production output is damaged in a sustainable fashion, that could have a durable impact on the economy.
TEPCO, the biggest power company in Japan, said on Sunday rolling blackouts would affect 3 million customers, including large factories and buildings from Monday onwards. It aims to end the blackouts by the end of April.
Policymakers face a monumental task reviving the economy, not only because of the scale of the disaster but because of their limited options.
Japan's political leaders have pushed for an emergency budget at time when the government is already fiscally constrained by a public debt twice the size of the economy, the biggest among advanced economies.
After the Kobe earthquake, the government adopted an extra budget worth around 3 trillion yen.
"This time, the government can't afford to spend as much as after the 1995 quake given Japan's dire fiscal situation," said Takuji Okubo, chief economist at Societe General in Tokyo, who reckons a more realistic figure to expect is 1 trillion yen.
The Bank of Japan's interest rates are already near zero -- a legacy of the global financial crisis and years of economic stagnation -- so it has limited room to cut again.
That is in stark contrast to New Zealand, where the central bank last week slashed interest rates by half a percentage point to 2.5 percent to support an economy hit by a 6.3 magnitude earthquake on February 22.
On Monday, the central bank pledged $183 billion to pump into the financial system to make sure the economy had sufficient cash.
The central bankers are reviewing policy on Monday and economists expect the most likely outcome of the meeting to be an expansion of a 5-trillion-yen pool of funds to buy assets, such as government bonds.
Still, some say the scale of the disaster will prompt the central bank to go further.
"The BOJ is likely to take bold steps to stabilize the financial system and is likely to revert to quantitative easing or zero interest rate policy," said Naomi Hasegawa, senior fixed-income strategist at Mitsubishi UFJ Morgan Stanley Securities in Tokyo.
The benchmark Nikkei stock average fell around 6 percent as concerns about rolling power blackouts hit the value of auto and electronics firms and the yen slid against the dollar.
Electronics giant Sony, maker of the Playstation gaming console, dropped 8 percent. The firm has suspended production at eight plants. Car maker Nissan Motor Corp fell more that 8 percent after it shut down all four of its auto assembly plants in Japan.
"It will take quite some time until investors confidence in Japanese manufacturers returns. When we look back at the Kobe earthquake, it took about a week to get an overall picture of magnitude of the damage," said Toshihiko Matsuno, senior strategist at SMBC Friend Securities.
The prospects of a massive recovery effort boosted contractor companies. Kajima Corp jumped more than 30 percent and Hazama Homes more than 40 percent.
The market ripples of Japan's disaster will be felt far beyond the country's shores.
Wall Street is braced to feel some impact as companies that trade with Japan face a loss of business and worries that governments will look at nuclear power less favourably. S&P 500 futures were down 0.3 percent on Monday.
Almost 2 million households are without power in the freezing north and about 1.4 million lack running water.
Kyodo news agency said 80,000 people have been evacuated from a 20-km (13 mile) radius around the stricken Fukushima nuclear plant, adding to 450,000 evacuees from the quake and tsunami.
An explosion rocked the number 3 reactor on Monday although Jiji news agency said the core container was intact. TEPCO shares were untraded as sell orders outnumbered bids 200 times.
The complex was rocked by a first explosion on Saturday, which blew the roof off a reactor building. The government had said further blasts would not necessarily damage the reactor vessels.
TEPCO said on Monday it had reported a rise in radiation levels at the complex to the government.
Authorities had been pouring sea water to keep the fuel rods in the reactors cool. Nuclear experts said it was probably the first time in the industry's 57-year history that sea water has been used in this way, a sign of how close Japan may be to a major accident.
"Injection of sea water into a core is an extreme measure," Mark Hibbs of the Carnegie Endowment for International Peace. "this is not according to the book."
(Additional reporting Tokyo bureau: Writing by Neil Fullick; Editing by Tomasz Janowski)