By Rodrigo Campos

NEW YORK (Reuters) - The S&P 500 edged lower on Monday as a four-week rally stalled, while a rebound in Apple shares helped buoy the Nasdaq.

Caterpillar <CAT.N> shares helped cap losses in the Dow industrials even as the company posted a 55 percent drop in quarterly profit due to a charge connected with accounting fraud at a Chinese subsidiary and weak demand among its dealers. Caterpillar's shares, down 2.2 percent in the past three sessions, rose 1.5 percent Monday to $96.97.

The S&P 500 is coming off a streak of eight sessions of gains, the longest in eight years. On Friday, the major U.S. stock indexes closed a fourth straight week of gains with the S&P 500 ending the session above 1,500 for the first time in more than five years.

The rally has left the market vulnerable to a short-term pullback of up to 3 percent in the S&P 500 as bullish sentiment continues to rise, according to Richard Ross, Auerbach Grayson's global technical strategist.

"Still," Ross said, "we have a lot of momentum and nice seasonality, and technicals support the long-term bull market."

Data on Monday pointed to growing economic momentum as companies sensed improved consumer demand.

Thomson Reuters data showed that of the 150 companies in the S&P 500 that have reported earnings so far, 67.3 percent have beaten analysts' expectations, which is a higher proportion than over the past four quarters and above the average since 1994.

The Dow Jones industrial average <.DJI> fell 9.02 points or 0.06 percent, to 13,886.96, the S&P 500 <.SPX> lost 1.5 points or 0.1 percent, to 1,501.46 and the Nasdaq Composite <.IXIC> added 8.46 points or 0.27 percent, to 3,158.17.

Bargain hunters lifted Apple <AAPL.O> after the tech giant's stock dropped 14.4 percent in the previous two sessions. With Apple's stock up 2.4 percent at $450.29, the iPad and iPhone maker regained the title as the largest U.S. company by market capitalization as Exxon Mobil <XOM.N> fell 0.9 percent to $90.94 and slipped back to second place.

"I think there is more downside in Apple if you did get a broad market pullback," Auerbach Grayson's Ross said.

"I'd be patient unless you're a trader. It might not be the most attractive entry point."

U.S. durable goods orders jumped 4.6 percent in December, a pace that far outstripped expectations for a rise of 1.8 percent. Pending home sales unexpectedly dropped 4.3 percent. Analysts were looking for an increase of 0.3 percent.

Equities have also gained support from a recent agreement in Washington to extend the government's borrowing power. On Monday, Fitch Ratings said that agreement removed the near-term risk to the country's 'AAA' rating.

Hess Corp <HES.N> shares shot up 5.3 percent to $62.02 after the company said it would exit its refining business, freeing up to $1 billion of capital. Separately, hedge fund Elliott Associates is looking for approval to buy about $800 million more in Hess stock.

Keryx Biopharmaceuticals Inc <KERX.O> said a late-stage trial of its experimental kidney disease drug met the main study goal, and its shares soared 67 percent to $5.75.

(Editing by Jan Paschal and Nick Zieminski)