Computer maker Dell did nothing to soothe investor concerns about a weakening tech sector Thursday, posting results that badly missed Wall Street's expectations.

The No. 3 PC maker released results after the close of regular trading. Earlier in the day, three Wall Street analysts said they see signs of slowing chip sales. One cut his rating on Intel (NasdaqGS:INTC - News), citing slowing PC shipments.

Dell (NasdaqGS:DELL - News) said it earned 23 cents a share, excluding one-time charges of 6 cents a share, for its fiscal third quarter ended Oct. 30. That's down 38% from a year ago and 5 cents lower than analysts had forecast.

The Round Rock, Texas-based company said sales fell 15% to $12.9 billion. Analysts polled by Thomson Reuters expected $13.2 billion.

Investors sent Dell shares falling 6% after hours, after the release.

In the regular session, Intel shares plunged as much as 5.8% before closing down 4.1%. National Semiconductor (NYSE:NSM - News) and Nvidia (NasdaqGS:NVDA - News) fell 4.2% and 4%, respectively. IBD's 118-stock chip group fell 2.9%, while the Philadelphia semiconductor index slipped 3.4%.

Dell shares dipped 1% to 15.87 in regular-session trading.

Dell tried to sugarcoat the results, but they were a letdown, says Shaw Wu, an analyst with Kaufman Bros.

"It was a disappointing quarter," Wu said. "Everyone expected them to beat (Wall Street forecasts).

"This quarter shows that the whole strategy of giving up some market share to pursue profitability is not quite driving the results that one would hope. Dell is probably losing more share than they envisioned."

And Dell's continued use of restructuring charges is frustrating, Wu says. "The earnings are not clear," he said. "They have all these charges again."

Dell reported earnings per share, under generally accepted accounting principles, of 17 cents. That included pretax expenses of 5 cents a share for "organizational effectiveness" actions and 1 cent a share for amortization of intangibles.

Dell Chief Financial Officer Brian Gladden said much of those one-time charges was related to shuttering the company's Winston-Salem, N.C., manufacturing plant.

The company focused on the positive, saying in its release that it saw sequential increases in demand and revenue from business customers last quarter.

"Our third-quarter results are showing some encouraging signs for us, especially in our large enterprise and (small and medium) businesses, where we had sequential growth for the first time in seven quarters," Gladden said on a conference call with the media.

"Our revenue grew sequentially for the second quarter in a row and we expect another sequential sales increase in the fourth quarter," he said.

Dell walked away from some retail PC business last quarter because the profit margins weren't acceptable, Gladden said.

"While we've been talking about demand stabilization in prior quarters, we're now seeing signs of improvement in some markets, including key commercial markets worldwide," he said.

It was Dell's fifth straight quarter of year-over-year sales declines. Earnings per share have shrunk for four straight quarters.

Dell, once the world's No. 1 maker of personal computers, fell to No. 3 behind Hewlett-Packard (NYSE:HPQ - News) and Acer in the quarter in global PC shipments, says market tracker Gartner.

Last quarter, Dell's desktop PC business performed the worst of all its businesses. That group's sales fell 26% from a year earlier and 9% from the preceding quarter. Its mobility, or laptop PC, unit saw sales rise 8% from the second quarter but fall 14% from a year ago.

Early Thursday, Bank of America Merrill Lynch, FBR and Avian Securities all said they see signs of slowing chip sales. They don't agree as to why, though.

Slowing PC shipments pose "a rising risk" to Intel and other chipmakers, BofA analyst Sumit Dhanda said in a note to clients. Dhanda on Thursday cut his rating on Intel to neutral from buy.

FBR's Craig Berger says output of the top five notebook makers in Taiwan is down from a month ago. Berger says long term he's bullish on chips, but that this slowdown is a bad sign for holiday sales. He rates Intel market perform, or neutral.

Avian Securities analyst Avi Cohen says chip sales are slowing because makers of PCs, cell phones and more have ended their pre-holiday buildup.

He says some memory chip prices are down, and that's a bit of a concern, but "Bank of America is making a big global call that the world is coming to an end. It might be, but there's no evidence of that," Cohen said in an interview. It will be early December, he says, before the first hard data on holiday sales come in.

Dell expects to get a bigger contribution this quarter from Microsoft's (NasdaqGS:MSFT - News) Windows 7 PC operating system, which launched Oct. 22.