US stocks fell on Wednesday as the government's effort to stave off a deep economic recession raised worries about mounting public debt.
Investors also continued to weigh whether the Federal Reserve had any ammunition left after its bold move to slash borrowing costs to a record low near zero while it pledged to use "all available tools" to jump-start the US economy.
Energy stocks were the top drag on the Dow after oil prices fell briefly below $US40 a barrel for the first time since July 2004.
The Dow Jones industrial average shed 99.80 points, or 1.12%, to 8,824.34.
The Standard & Poor's 500 Index fell 8.76 points, or 0.96%, to 904.42.
The Nasdaq Composite Index fell 10.58 points, or 0.67%, to 1,579.31.
However, advancing shares outnumbered declines on the NYSE by a ratio of about 3 to 2, while on the Nasdaq, the ratio was roughly even.
The Dow is down 37.7% from its record close in October of 2007 and 33.5% for the year-to-date.
Weighing on the Nasdaq, Apple Inc slid nearly 7% after the company said chief executive Steve Jobs would not give the keynote address at the Macworld trade show, renewing concerns about his health.
Financial stocks were unable to sustain their gains despite an analyst note that said Morgan Stanley's poor results announced on Wednesday were not likely to be repeated.