US stocks traded lower Tuesday as earnings season was set to begin, with investors cautious after the economy plodded along during the fourth quarter of 2012.
At 11:00 am (1600 GMT) the Dow Jones Industrial Average was down 64.08 points (0.48 percent) at 13,320.21.
The broad-based S&P 500 fell 8.68 (0.59 percent) to 1,453.21, while the tech-heavy Nasdaq Composite lost 16.86 (0.54 percent) at 3,081.95.
Monsanto shares surged 2.7 percent after reporting a 169 percent rise in profit for its quarter to November 30 on strong genetically modified corn seed sales in the US and Latin America.
Biotech and pharmaceutical company Celgene gained 3.5 percent after raising its guidance for 2012 income and earning an upgrade from analysts at RBC Capital markets.
Boeing shares fell 1.4 percent as attention focused on a fire that broke out in one of its new 787 Dreamliner aircraft as it sat empty at a Boston airport on Monday.
Verizon and AT&T, each down 1.6 percent, fell on worries that smaller rival T-Mobil could mount a potent challenge to their business model by ending subsidies on smartphones sold to new subscribers.
Fast food franchiser Yum Brands, which controls Pizza Hut, Taco Bell and Kentucky Fried Chicken, lost 4.4 percent after divulging that its China business, the source of strong growth in recent years, would be hit in fourth-quarter reporting by a slowdown in KFC sales.
Bond prices gained. The yield on the 10-year US Treasury fell to 1.86 percent from 1.91 percent late Monday, while the 30-year moved down to 3.06 percent from 3.10 percent. Bond prices and yields move inversely.