The Nikkei stock average tumbled below 15,000 Monday as shares fell broadly amid fears of a possible synchronized global stock market rout.

With Wall Street's precipitous falls in recent days weighing heavily on investor sentiment, the benchmark Nikkei average, which at one point had plunged more than 460 points, ended down 329.27 points, or 2.2 percent, at 14,794.66 -- its lowest reading since June 17.

The yen in interbank trading in Tokyo was trading at 146.46-48 against the dollar at 3 p.m. compared with 144.87-90 late Friday as repeated warnings by government officials against speculative attacks on the currency again went unheeded.

The Tokyo Stock Exchange has moved lower almost daily since the beginning of August, and the 225-issue Nikkei average now sits just about where it did at the start of the year.

Besides global financial fears, market players remain obsessed over worries about unnerving reports from all domestic corners, among them rising unemployment and bankruptcies.

The beleaguered banking industry itself has sparked concern over its health, and there is speculation that the ongoing inspections by the Financial Supervisory Agency of nine major banks will force some out of business.

Many firms have gone under in recent months, blaming their failures on credit-tightening at lending institutions.