(Updates to midafternoon, changes byline)
* Tech advances after upbeat Dell, Marvell earnings
* Global tech demand offsets U.S. weakness
* Volatile oil price sparks caution
By Ellis Mnyandu
NEW YORK, May 30 (Reuters) - U.S. technology shares rose on Friday as investors took computer maker Dell Inc's <DELL.O> upbeat profit as signaling that business spending was holding up, boosting optimism about the outlook for big-cap tech companies.
But even with the tech advance, volatile crude oil prices spurred uneasiness, keeping the S&P 500 <.SPX> and the Dow Jones industrial average <
> at break-even.Since oil prices hit a record above $135 barrel last week, investors remain concerned about the effect of soaring fuel costs on inflation and on consumer spending, a key driver of economic growth.
In addition, data on Friday showed that consumer confidence fell to a 28-year low in May.
Still, Dell shares jumped more than 6 percent, putting the stock among the Nasdaq composite index's top boosters, along with chip designer Marvell Technology Group Ltd <MRVL.O>, up more than 24 percent, thanks to stronger-than-expected earnings.
The semiconductor index <.SOXX> , up 2.3 percent, was on track for its second straight monthly advance, which will cap its longest winning monthly streak since October 2006.
"The strength of Dell's numbers was a pleasant surprise," said Georges Yared, founder and chief investment officer at Yared Investment Research in Wayzata, Minnesota.
"What this demonstrates is that technology spending is very strong globally. It may not be as strong domestically, but U.S. weakness is being offset by global demand. So tech is probably positioned now for a very good second quarter."
The Dow Jones industrial average <
> gained 3.91 points, or 0.03 percent, to 12,650.13. The Standard & Poor's 500 Index <.SPX> climbed 3.41 points, or 0.24 percent, to 1,401.67. The Nasdaq Composite Index < > shot up 17.71 points, or 0.71 percent, to 2,526.03.Dell shares rose to $23.28 on Nasdaq, while Marvell shares rose to $17.51. Contributing most to Nasdaq's rise were shares of iPod and iPhone maker Apple Inc <AAPL.O>, up 1.2 percent at $188.89.
Shares of Cisco Systems Inc <CSCO.O>, whose routers and other networking gear form a backbone of corporate networks, were the biggest contributor to the S&P 500's rise, up 2.1 percent at $26.75 on Nasdaq.
Computer maker Hewlett-Packard Co <HPQ.N> led the Dow's tech components with a gain of 1.1 percent to $47.41 on the New York Stock Exchange.
Shares of American International Group Inc <AIG.N> were the biggest percentage gainers on the Dow, up more than 2 percent at $36.14 on the NYSE, after Morgan Stanley said the recent decline in the insurer's stock was overdone and raised its rating. For details, see [
]Shares of consumer-oriented companies like retailers were among the top drags, with shares of Costco Wholesale Corp <COST.O>, the leading U.S. warehouse club operator, down more than 2 percent at $71.40 after Piper Jaffray cut its rating on the stock.
Shares of Coca-Cola Co <KO.N>, the world's largest soft-drink company, declined 1.1 percent to $57.24 on the NYSE, while rival PepsiCo Inc <PEP.N> slipped 0.7 percent to $68.38.
U.S. crude <CLc1> gained 76 cents, or 0.6 percent, at $127.38 a barrel on the New York Mercantile Exchange.
In economic news, the core personal consumption expenditures price index -- the Federal Reserve's preferred measure of inflation -- moderated in April from the previous month, easing inflation fears.
But a Reuters/University of Michigan gauge of consumer confidence fell to a 28-year low in May, keeping stock gains in check. A separate report showed business activity in the U.S. Midwest contracted for May for the fourth consecutive month, but the rate of downturn moderated. (Editing by Kenneth Barry)