* Caterpillar rallies after fourth-quarter results
* S&P 500 dips after eight straight sessions of gains
* Bargain hunters snap up Apple following recent drop
* Dow up 0.03 pct, S&P 500 down 0.01 pct, Nasdaq up 0.4 pct
NEW YORK, Jan 28 (Reuters) - The Standard & Poor's 500 edged lower on Monday as a four-week rally stalled, while a rebound in Apple shares helped buoy the Nasdaq.
Caterpillar shares helped cap losses in the Dow industrials after the heavy equipment maker's outlook eased investors' fears about an economic slowdown in China. Caterpillar's shares rose 2.1 percent to $97.61.
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. Since 1994, 62 percent of companies have topped expectations, while the average over the past four quarters stands at 65 percent.
The Dow Jones industrial average rose 4.34 points, or 0.03 percent, to 13,900.32.. The S&P 500 shed 0.19 of a point, or 0.01 percent, to 1,502.77. The Nasdaq Composite added 11.40 points, or 0.36 percent, to 3,161.11.
Bargain hunters lifted Apple after the tech giant's stock dropped 14.4 percent in the previous two sessions. With Apple's stock up 2.8 percent at $452, the iPad and iPhone maker regained the title as the largest U.S. company by market capitalization as Exxon Mobil fell 0.9 percent to $90.90 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 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 shares shot up 5.7 percent to $62.27 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 said a late-stage trial of its experimental kidney disease drug met the main study goal, and its shares soared nearly 60 percent to $5.45.