The tumble in Tokyo share prices to 19-year lows Wednesday is likely to deal a severe blow to the finances of Japanese banks and corporations.

Corporations can expect little help from the nation's major banks if the current descent in share prices continues, according to analysts. If their credit spigots go dry, corporations would be forced to cut back on expenditures, thereby triggering a downward spiral in the economy.

"The economy is in for a long haul of stagnation," said Yasunari Ueno, chief market economist at Mizuho Securities Co.