* U.S. jobless claims rise modestly in latest week
* China stocks fall despite Beijing's economic reforms
* GM profit beats on strong U.S. demand, smaller loss in Europe
* Facebook shares surge following results
* Indexes: Dow down 0.5 pct; S&P off 0.3 pct; Nasdaq up 0.3 pct
By Angela Moon
NEW YORK, July 25 (Reuters) - U.S. stocks fell on Thursday, with the S&P 500 index falling for a third consecutive day as mixed earnings and concerns about China's economic slowdown weighed on investor sentiment.
Results from General Motors and Dow Chemical were generally positive on Thursday. But no quarterly profits so far, with the possible exception of big U.S. banks', have been so spectacular as to give stocks a major boost.
Heavy equipment maker Caterpillar Inc's gloomy outlook on Wednesday weighed on the market.
"Most people know that the bar is low (for profit), and what's more important is the revenue, the outlook and we are getting mixed signals on that. Investors are responding with increased sensitivity to these numbers," said Andrew Wilkinson, chief economic strategist at Miller Tabak & Co in New York.
Growing worries about a hard landing for China's economy also made U.S. investors nervous. Chinese stocks suffered their second straight loss on Thursday despite measures from the government to spur the economy, including help for exports and railway investment. Data on Wednesday showed manufacturing in China running at an 11-month low in July.
Investors also booked profits from a recent rally that has taken the S&P 500 up 18 percent for the year. Despite a back-to-back decline in the past two days, the index is still near its all-time high.
The Dow Jones industrial average was down 70.04 points, or 0.45 percent, at 15,472.20. The Standard & Poor's 500 Index was down 4.62 points, or 0.27 percent, at 1,681.32. The Nasdaq Composite Index was up 0.34 points, or 0.01 percent, at 3,579.94.
Nasdaq was boosted by shares of Facebook which jumped nearly 26 percent to $33.44, a day after the company announced earnings.
In yet another heavy day of earnings, General Motors Co posted a stronger-than-expected quarterly profit on demand in North America and cost-cutting in its struggling European business. The stock rose 0.3 percent to $37.26.
Dow Chemical Co's adjusted quarterly profit jumped 16 percent, topping analysts' estimates, driven by robust demand for pesticides. The stock was up 1.5 percent at $34.90.
But not-so-stellar results from bellwethers like Caterpillar and AT&T on Wednesday triggered concerns about the profit outlook. Caterpillar shares were down 1.2 percent at $82.40 and AT&T shares were flat at $35.41 on Thursday.
Data showed the number of Americans filing new claims for jobless benefits rose slightly last week in a sign the U.S. labor market continues to improve at a moderate pace while new orders for durable goods rose by 4.2 percent in June. Market reaction was muted.
In Europe, shares fell as a raft of mixed results from blue chips and lingering concerns about the pace of growth in China triggered a bout of profit taking following recent sharp gains.