Stocks were modestly lower on Monday as investors fretted about the impact of slower global growth on corporate revenues, offsetting earnings that beat expectations.

Technology stocks bucked the general downward momentum, with Apple Inc (AAPL.O) helping to push the Nasdaq higher.

Caterpillar's (CAT.N) shares seesawed after the heavy equipment maker became the latest to exceed expectations on the bottom line but fall short of revenue forecasts. The stock fell early but was most recently up 1.5 percent at $85.16.

The market is caught in a push-pull between earnings that are beating lowered expectations while revenues come in weak, said Brian Gendreau, market strategist with Cetera Financial Group in Gainesville, Florida.

"I think the market is focusing on that, they're looking for the top line rather than the bottom line," said Gendreau.

Of the 123 S&P 500 companies that have reported results, 60.2 percent have topped analysts' expectations for earnings, but 61 percent have missed on revenue forecasts, according to Thomson Reuters data.

Third-quarter earnings are expected to fall 2.4 percent from a year ago.

Caterpillar Inc, the world's largest maker of tractors and excavators, slashed its 2012 forecast for the second time this year, warning the global economy was slowing faster than it had expected.

"These companies are running lean and mean, very productive and very efficient, but you're not getting that revenue growth" in the midst of the sovereign debt crisis in the euro zone and slower growth in China, said Alan Lancz, president of Alan B. Lancz & Associates Inc in Toledo, Ohio.

The S&P appeared once again to be testing the 50-day moving average around 1,434, which has proven to be a strong support level. A convincing break below could signal further declines.

Mining company Freeport-McMoRan (FCX.N) lost 1.3 percent to $40.63 after it said third-quarter profit fell sharply, missing Wall Street estimates, due to a big drop in gold production in Indonesia.

The Dow Jones industrial average .DJI slipped 28.53 points, or 0.21 percent, to 13,314.98. The Standard & Poor's 500 Index .SPX was off 3.19 points, or 0.22 percent, to 1,430.00. The Nasdaq Composite Index.IXIC added 3.81 points, or 0.13 percent, to 3,009.43.

Nine of 10 S&P 500 industry sectors were lower, with only information technology higher, in part due to gains in Apple, which rose 2.4 percent to $624.31. Other tech gainers included Oracle (ORCL.O), up 0.8 percent at $30.71.

Coal miner Peabody Energy Corp's (BTU.N) third-quarter profit beat analysts' expectations as improved U.S. margins and higher Australian sales volumes offset price declines. The stock rose 12.2 percent to $29.05.

Ancestry.com Inc (ACOM.O) jumped 7.8 percent to $31.47 after the company said it will be acquired by a group led by Europe-based private equity firm Permira in a $1.6 billion deal.

After the closing bell, earnings reports are expected from Yahoo Inc (YHOO.O) and Texas Instruments Inc (TXN.O). There are 155 S&P 500 components scheduled to report earnings this week.