Copper Rally Fades

Updated from 12:07 p.m. EDT

Copper prices popped up in early trading Friday as London Metal Exchange stockpiles shrank again and sales of existing homes unexpectedly rose.

But the rally was short-lived and contracts for May delivery of the metal closed unchanged at $3.07 a pound in New York. The PowerShares DB Base Metals (DBB Quote) exchange-traded fund, which tracks other metals as well as copper, slipped 0.6%.

The National Association of Realtors reported better-than-forecasted sales of previously owned homes in February, but Randy Diamond, an analyst at Miller Tabak in New York, notes that the inventory of unsold dwellings ballooned to near a record level.

Even so, and although the U.S. housing market has historically been a key demand segment for copper, new markets appear to be taking up any slack.

In particular, its use in manufacturing window-unit air conditioners for installation in China's soaring tower blocks is a critical factor, according to Don Coxe, global portfolio strategist at BMO Financial Group in Chicago. Because of copper's superior heat-conducting properties, it remains the metal of choice for cooling equipment even at elevated prices, he says.

Elsewhere, the Manhattan-based Economic Cycle Research Institute says its weekly leading index grew 3.9% last week, auguring well for a fair economic climate in the months ahead. But it also stands in sharp contrast to the Conference Board's index of leading economic indicators, which registered a drop of 0.5% in February, when it was published Thursday.