US copper fell to near the day's lows in late trade on Wednesday, erasing most of the session's gains after the US Federal Reserve launched a widely expected $400 billion plan to buy long-term Treasuries while warning of "significant" dangers to the economy.
In New York, the December COMEX contract surrendered its 1-percent gain on the day and fell back toward session lows in after-hours trade near $3.7075 per lb.