Dow Jones Industry Average Index extended previous losses on Tuesday, falling 0.82% to trade at 12,617.32. All sectors within the index tumbled. The largest decliners were basic materials and oil and gas sectors. Chevron fell 1.53% despite slight increase in oil price after positive China's PMI data release. EI du Pont de Nemours & Co dropped 1.99% after reporting a 3% decrease in profit in Q2 amid weaker business in the EU and Asia. Shares of AT&T slid 2.12% as the company's revenues and earnings in Q2 missed expectations. Meanwhile, Cisco Systems declined the most of the Dow Jones stocks after the network equipment producer reported its latest round of staff reduction.