Copper added to its session gains in late trade on Wednesday, buoyed after the US Federal Reserve statement left interest rates unchanged and said it would keep its $600 billion bond-buying plan intact. "The economic recovery is continuing, though at a rate that has been insufficient to bring about a significant improvement in labour market conditions," the Fed said in a statement.
COMEX March copper on the New York Mercantile Exchange peaked at $4.29 per lb in electronic business, about a half percent higher than its settlement at $4.2670 per lb.