U.S. stocks mostly slipped on Friday after a weak consumer sentiment report offset positive quarterly results and outlooks, while some investors booked profits after the Dow's eight-day winning streak.

But the Nasdaq clung to a tiny gain, with support from bellwethers Dell Inc and Intel Corp .

With the three major indexes up about 50 percent from multi-year lows in March, investors are concerned that the rally may have run its course, and that with many market players taking last-minute vacations, there aren't enough buyers to push stocks up further.

Consumer sentiment in August slid to a four-month low on worries about high unemployment and personal finances, a Reuters/University of Michigan survey showed, also curbing the market's appetite for risk.

Expectations are higher and any kind of data that doesn't exceed forecasts with rosy numbers can't move the market, said Alan Lancz, president of Alan B. Lancz & Associates in Toledo, Ohio.

I think the absence of buyers is triggering traders to sell into the weekend. Next week is basically the last week of the summer, and with more buyers away, there would be fewer catalysts of bull momentum.

The Dow Jones industrial average <.DJI> was down 39.83 points, or 0.42 percent, at 9,540.80. The Standard & Poor's 500 Index <.SPX> was down 1.95 points, or 0.19 percent, at 1,029.03. But the Nasdaq Composite Index <.IXIC> was up 2.96 points, or 0.15 percent, at 2,030.69.

The losses were broad-based, with health-care stocks leading the declines. Merck & Co Inc was down nearly 2 percent at $32.24. The S&P health care index <.GSPA> was off 1 percent.

Among the blue-chip Dow industrials, McDonald's Corp ranked among the top losers, falling 1.4 percent to $55.88.

Intel led the Nasdaq's major gainers and helped the index nudge back into positive territory in late afternoon trading. Intel's stock climbed 4.2 percent to $20.29 after it raised its third-quarter revenue outlook on stronger-than-expected demand for its microprocessors and chipsets.

Dell rose 2.5 percent to $16.05 and Marvell Technology gained 4.4 percent to $15.27, after both companies late Thursday reported second-quarter earnings that beat expectations.

But Novell Inc lost 6.4 percent to $4.41 on Nasdaq after posting a slightly worse-than-expected decline in quarterly revenue.

Tiffany & Co surged 11 percent to $37.46 in New York Stock Exchange trading after it reported strong second-quarter results and lifted its outlook.

The fact that Tiffany and Dell -- which represent tech and luxury spending -- failed to ignite the market shows that traders are cautious, given the run the market has had, said Jim Awad, managing director at Zephyr Management in New York.

Citigroup rose 3.6 percent to $5.23 and the S&P financial index <.GSPF>, one of the few sectors among Friday's advancers, edged up 0.1 percent.

Shares of the two largest U.S. home funding companies, Fannie Mae and Freddie Mac, gained sharply, extending a trend seen earlier this week. Freddie Mac was up 7.1 percent at $2.38 and Fannie Mae gained 6.3 percent to $2.05.

The stock market turned negative after the consumer sentiment data was released. Previously, the S&P 500 climbed to 1,039.47, its highest intraday reading since October 14, 2008.

In other data released on Friday, a report from the Commerce Department showed consumer spending edged up 0.2 percent in July, largely driven by the government's cash-for-clunkers program, while personal incomes were flat in June.

(Reporting by Angela Moon; Editing by Jan Paschal)