Wal-Mart fell 2.2 per cent after reporting lower revenue and cutting its profit forecast for 2013. Cisco plunged 7 per cent after the network equipment maker's outlook missed analysts' estimates. The company also said it would slash 4,000 jobs.
The Dow was down 173 points, or 1.1 per cent, to 15,164 shortly before noon Thursday. It was down 230 points earlier.
The Standard & Poor's 500 index lost 18 points, or 1.1 per cent, to 1,666.
The Nasdaq composite fell 47 points, or 1.3 per cent, to 3,622.
The yield on the benchmark 10-year Treasury note jumped to 2.80 per cent, the highest since July 2011.