Copper futures were trading lower in after hour electronic trading after ending Tuesday with gains on a rising dollar.
Earlier copper futures rose as the dollar fell 1 percent against major currencies. However a lack of inventories weighed more on prices as investors fear demand from China the top consumer of copper in the world, is slumping. Stockpiles in the London Metal Exchange have increased 11 percent in this year.
China's Customs Office said copper imports from the country decreased 19 percent in the first quarter of 2008 compared to the previous year.
Copper futures for July delivery were trading 0.1 cent or 0.03 percent down to $3.7755 a pound on the Comex division of the New York Mercantile Exchange during electronic trading. During the day the red metal fell as much as 1.2 percent on demand concerns.
Supporting prices, a report on Tuesday from the Labor Department said that U.S. wholesale prices jumped in April 0.4 percent more than the 0.2 percent forecasted by analysts according to a Bloomberg survey. The results rose concerns that demand will weaken.
Copper futures for delivery in three months rose $10 or 0.12 percent to $8,383 a metric ton in the London Metal Exchange.