Intel (INTC) - Get Report slid sharply in after-hours trading after the chip giant warned after the close Thursday that third-quarter revenue would fall short of estimates.

Intel said it expects third-quarter revenue to rise 3% to 5% from the second quarter's $8.3 billion. The Santa Clara, Calif., chipmaker said third-quarter gross margin would also fall below estimates, at 62% vs. the previous 63%-64% guidance. The company blamed weaker-than-expected demand in Europe, a problem that a number of other big U.S. multinationals have

warned of in recent weeks.

Intel slid $1.58, or 2.5%, to close at $61.48 Thursday. In after-hours trading on

Island ECN

, Intel was quoted off $11.48, or 19%, at $50.

Intel's bad news precipitated a techwide selloff after the market closed Thursday. Leading tech stocks were topping Island's list of most-active after-hours stocks: Internet incubator

CMGI

(CMGI)

was down $1.69 at $34.81, networker

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Cisco

(CSCO) - Get Report

was off $3.06 at $58.13, PC giant

Dell

(DELL) - Get Report

was down $4.13 at $33.88, and opticals concern

JDS

(JDSU)

was down $4.56 to $98.88. With the

Nasdaq

selling off this month on the heels of August's rally, the Intel warning could spell more trouble for tech stocks.