Shares on word stock markets tumbled today after global investment banking group Lehman Brothers, one of the world's biggest banking groups, announced it plans to file for bankruptcy protection.
The Dow Jones Industrials in New York closed nearly 500 points lower - its worst point drop since the September 2001 terrorist attacks.
Last minute selling saw the Dow close down 4.42 per cent or 504.48 points to 10,917.51 moving below the 11,000 mark for the first time since mid-July.
The Dublin market shed over 240 points or 5.6 per cent earlier in response to the news but this afternoon the Iseq index rallied to 4,228, to be 116 points down on the day.
However Dublin analysts predicted the index may fall through the 4,000 mark in the coming weeks. All but four the 60-quoted stocks were either down or unchanged by mid-afternoon.
Stocks in Europe, Asia and South America also plunged on the Lehman news and as Bank of America's weekend agreement to buy Merrill Lynch stirred concerns about mounting global economic problems.
The dollar slumped on the wide aversion to risk, posting its biggest one-day drop against the yen in nine years.
European shares slid to their lowest close in two months. Most major Asian markets were closed for a holiday, but stocks fell heavily on open markets.
Shares of financial services companies plunged on concerns about the impact of the credit crisis on their profit outlooks and the broader economy. Such worries also led to the view that energy demand would slow further, dragging down oil prices.
New York crude prices fell by $5.47 to settle at $95.71, after earlier hitting a seven-month low of $94.13 a barrel.
The Dow Jones industrial average closed down 504.48 points, or 4.42 per cent, at 10,917.51. The Standard & Poor's 500 Index lost 58.06 points, or 4.64 per cent, at 1,193.64. The Nasdaq Composite Index shed 81.36 points, or 3.60 per cent, at 2,179.91.
"The turmoil continues," said Robert Francello, head of equity trading for Apex Capital hedge fund in San Francisco. "And it seems to be people underestimated the impact of AIG and what the fallout of that could be."
Shares of Lehman plunged almost 95 per cent in composite trade. American International Group plummeted about 50 per cent as investors grew increasingly wary after the insurer, once the world's most valuable insurer by market value, failed to deliver a rescue plan.
Lehman, weighed by losses spawned by the US mortgage crisis, sought bankruptcy protection on Monday following a failed last-minute scramble to find a buyer over the weekend.
Adding to investor worries was a report that AIG had asked the Federal Reserve for a $40 billion bridge loan.
AIG shares closed at $4.76 after falling as low as $3.50 during the session.
The Standard & Poor's 500 Index broke through the psychological barrier of 1,200 set on July 15 when markets were gripped by a previous bout of fear.
Institutional investors are waiting to see what happens to AIG if the Federal Reserve cuts interest rates at its policy-setting meeting on Tuesday and if a European bank is hit by the resurgent credit crisis, traders said.
"There's a lot of cash on the sidelines and they're waiting to put it into use but there's no impetus for them to do it," said Edward Craig, head of US cash equities trading at Jefferies & Co in New York.
In Europe, financial stocks weighed heavily on markets. The FTSEurofirst 300 index of top European shares ended with a loss of 3.63 per cent at 1,119.94 points, its lowest close since July 16. Falling stocks led gainers by about 10-to-one, according to Reuters data.
HBOS, Britain's largest mortgage lender, plunged 17.6 per cent, UBS fell 14.5 per cent and the Royal Bank of Scotland 10 per cent.
A steep fall in crude oil prices hit index heavyweight energy stocks such as Total, down 5 per cent, and Royal Dutch Shell, off 4.4 per cent.
Oil plunged as much as $7 per barrel as investors sought safer havens and on early signs that Hurricane Ike had spared key US energy infrastructure along the Gulf of Mexico.
"It has been quite a spectacular turn of events at Lehman and Merrill and the stresses in the financial system are sparking concerns about economic outlook and how that will weigh on global energy demand," said David Moore, commodities strategist for Commonwealth Bank of Australia.
In currency markets, the dollar had managed to hold gains against the euro for most of the New York session but as US benchmark indexes fell more than 3 per cent in late New York trading, the US currency fell in its wake.
The dollar fell 2.8 per cent to 104.92 yen in late New York trading, the biggest one-day drop against the yen since August, 1999, according to Reuters data.
The euro rose 0.6 per cent to $1.4308, though it remained off the session high of $1.4479.
The high-yielding Australian and New Zealand currencies fell sharply versus both the dollar and the Japanese yen.
Seen also as a safe-haven, the Swiss franc rose against the dollar, which fell 0.8 per cent to 1.1203 francs.
Deep fears about the unfolding US banking crisis drove up demand for US Treasury bills and pushed down yields, which move in the opposite direction to prices, on an intense flight-to-safety bid into ultra-short-term government paper.
The price of benchmark 10-year US Treasury notes jumped 2 points, a rare gain for longer-dated debt. The yield on the 30-year Treasury bond fell below 4.10 per cent for the first time since 1963.
"People are really scared. They don't trust many companies. They don't know how safe their money is," said Charles Zhang, managing partner at Zhang Financial in Portage, Michigan.
The price on two-year Treasury notes, most sensitive to the market's Fed policy outlook, was up 26/32 at 101-3/32. The yield fell to 1.80 per cent, down 42 basis points from Friday. The single-day drop in two-year yields was the biggest since the market session right after the Sept 11, 2001, attacks.
Gold futures ended 2.9 per cent higher in volatile trade. Gold contracts for December settled up $22.50 at $787.00 an ounce in New York.
The US - which has shed more than 100,000 financial-sector jobs this year - must now brace for up to 50,000 more.