U.S. shares headed toward three-month lows, mirroring declines in equities around the world after China weakened its currency, stoking investor concern that weakness in the world’s second-largest economy will drag down global growth. Energy and raw-material companies in the Standard & Poor’s 500 Index sank at least 2.6 percent as China’s move revived the angst that sent financial markets into turmoil last summer. Chevron Corp. declined 4 percent, while copper producer Freeport-McMoRan Inc. slid 6.3 percent. Losses were broad as all 10 of the benchmark’s main industries retreated. The S&P 500 lost 1.1 percent to 1,995.07 at 12:35 p.m. in New York, on track for its lowest level since Oct. 14. The Dow Jones Industrial Average fell 213.63 points, or 1.3 percent, to 16,945.03, with the gauge on pace for its worst three-day start to a year since 2008. The Nasdaq Composite Index dropped 1 percent. Trading in S&P 500 shares was 22 percent above the 30-day average for this time of day. Source : Bloomberg