NEW YORK (CNN/Money) - U.S. stocks headed toward a dour opening Thursday amid near-record oil prices, lackluster results from the world's largest retailer and a profit warning from a tech heavyweight.

At about 8:50 a.m. ET Thursday, Nasdaq and S&P futures were sharply lower, after being higher for much of the overnight period.

U.S. crude prices gained as U.S. and Iraqi forces began an offensive against insurgents in Najaf. Futures rose 17 cents to $44.97 a barrel in electronic trading, holding below the $45.04 record set Tuesday.

Brent oil futures were 30 cents higher at $41.87 a barrel in London after touching a record $42 earlier in the session.

In corporate news, earnings from Wal-Mart Stores (WMT: Research, Estimates) also appeared to give some investors pause as the world's largest retailer reported a profit that topped analysts' estimates, but sales came in softer than some estimates.

A week earlier than expected, Hewlett-Packard (HPQ: Research, Estimates) reported a third-quarter profit that missed Wall Street's estimates. The company also warned that its fourth-quarter profit will fall short of analysts' estimates as well.

After the market close, leading personal computer maker Dell (DELL: Research, Estimates) is set to report results.

Media conglomerate News Corp. (NWS: Research, Estimates) late Wednesday reported a gain in earnings, as did its majority owned U.S. studio and network, Fox Entertainment Group (FOX: Research, Estimates). But more modest sales gain guidance going forward sent shares of News Corp. lower in Australian trading Thursday.

Wednesday was a tough day for tech stocks, thanks to Cisco Systems (CSCO: Research, Estimates)' lackluster sales forecast. The Nasdaq composite index slid 1.5 percent. But the Dow Jones industrial average was down just 6 points (see chart for details).

Economic reports due Thursday include the reading on retail sales in July and the latest on unemployment claims.

Retail sales rose 0.7 percent in July, the government said Thursday, a weaker-than-expected increase for the month.

Last month's gain followed a decline in June, when sales fell a revised 0.5 percent, smaller than the 1.1 percent decline as originally reported, according to the Commerce Department.

For details of Wednesday's tech loss, click above.

Excluding autos -- which account for about a quarter of total sales and can fluctuate widely from month to month -- sales rose 0.2 percent versus a revised 0.3 percent gain in June. Economists on average had expected total sales to rise 1.1 percent and sales excluding autos to rise 0.4 percent, according to Briefing.com.

Initial claims for unemployment insurance fell to 333,000 in the week ended Aug. 7, the Labor Department reported, down from 337,000 the previous week. Economists expected a reading of 340,000, according to Briefing.com.

Asian-Pacific stocks were mixed in Thursday trading, with Tokyo's Nikkei index down 0.2 percent. European markets turned mixed in midday trading. (Check the latest on world markets)

Treasury prices were flat, with the 10-year note yield at 4.27 percent. The dollar pulled back against the yen and euro. Gold was higher.