Copper drifted lower on Thursday as the dollar strengthened after the US Federal Reserve gave no hint of further monetary support even as it acknowledged the world's biggest economy was recovering more slowly than it had expected. Shanghai's most-active September copper eased 0.3 percent to close at 67,270 yuan a tonne, also off the session low of 66,640.
But the outlook for copper and other base metals remains healthy on tight global supplies and firm demand from top consumer China, analysts said.