NEW YORK (CNN/Money) - U.S. stocks staggered at the open Wednesday as already shaky investor confidence took another shot from Oracle's tepid guidance and a warning from J.P. Morgan Chase.

Around 9:35 a.m. ET, the Dow Jones industrial average lost 73.87 to 8,133.68 . The Nasdaq composite dropped 16.80 to 1,243.12. The Standard & Poor's 500 index gave back 8.93 to 864.59.

Dow component J.P. Morgan (JPM: down $2.36 to $19.19, Research, Estimates) late Tuesdaywarned that its third-quarter profit will fall below its second-quarter result, citing bad loans and sluggish trading revenue, and did not rule out the possibility of job cuts. Compounding the problems for the company, credit rating agencies Standard & Poor's and Fitch Ratings downgraded J.P. Morgan's $42.4 billion in debt.

Several brokerages rushed to cut estimates on the investment bank. Credit Suisse First Boston trimmed its 2002, 2003 and third-quarter estimates on J.P. Morgan, citing higher credit costs and weaker trading profits. Merrill Lynch also cut its 2002 and 2003 estimates, while Goldman Sachs lowered its 2002 and 2003 estimates on the firm.

Lackluster forward guidance from software maker Oracle (ORCL: down $0.97 to $8.06, Research, Estimates) did not look invigorate the software sector Wednesday. Oracle late Tuesday posted a first-quarter profit in line with forecasts, but revenue was slightly below projections. The company said its second-quarter earnings and revenue is expected at the low end of analysts' expectations.

Merrill Lynch reduced its fiscal 2003 and 2004 earnings and revenue estimate for Oracle, while Goldman Sachs trimmed its 2003 estimates.

"Visibility beyond the upcoming quarter is minimal, but we continue to believe that we will see year-over-year improvements," said Jeff Henley, Oracle's chief financial officer.

The Dow began the session at 8,207.55, having lopped off 2 percent in Tuesday's session on growing concerns about the economy and corporate earnings. The Nasdaq composite index was nearly 16 points lower Tuesday.

European markets were sharply lower at midday led by weakness in banking and insurance stocks, while Asian-Pacific stocks closed lower Wednesday, following the lead of the U.S. markets. Tokyo's Nikkei index was down 0.8 percent, and might have suffered more except for the Bank of Japan's surprise decision to buy corporate shares held by Japanese banks.

The decline in equity markets continues to be reflected in Treasurys, with the 10-year note yield dipped to 3.81 percent from 3.86 percent late Tuesday, the lowest levels in four decades. The dollar weakened against the yen and euro.

Brent oil futures gained 27 cents to $29.32 a barrel in London, buoyed by fresh U.S. data from the American Petroleum Institute indicating a sharp drop in oil inventories.

In the morning's economic reports, data show that inflation at the consumer level remains a distant threat in an economy struggling to emerge from recession.

The Labor Department said its consumer price index, which measures retail prices paid by consumers, rose 0.3 percent after rising 0.1 percent in July. Excluding food and energy prices, "core" CPI also rose 0.3 percent after rising 0.2 percent in July. Economists expected a 0.2 percent rise in both CPI and core CPI, according to Briefing.com.

In a separate report, the Commerce Department said the trade gap, which measures the difference between imported and exported goods and services, saw a narrower-than-expected contraction to $34.5 billion in July from $37.16 billion in June.