Oct 25, 2012 (Dow Jones) NEW YORK--Copper's slide continued for a sixth straight trading day Thursday, with prices setting a seven-week low amid eroding support from equities and the euro.

The most actively traded contract, for December delivery, fell 1.75 cents, or 0.5%, to settle at $3.5505 a pound on the Comex division of the New York Mercantile Exchange. Copper prices have lost 5.3% over their six day slide.

The Dow Jones Industrial Average was trading just 9 points into positive territory, at 13086, as Comex copper trading was closing at 1 p.m. ET. The weaker tone to equity markets weighed on copper, as both assets tend to move in the same direction because investors consider them barometers of the economy.

Currency markets added to the downbeat mood, with the euro down on the day to trade below $1.30. Copper is priced in dollars and tends to lose the interest of investors who fund their purchases through other currencies when the dollar strengthens, because dollar-denominated assets become more expensive to them.

Earlier in the day, copper had edged higher on brighter U.S. economic data. U.S. durable goods orders posted their largest increase in two and a half years in September, rising 9.9%, while a separate report showed pending home sales rose 0.3% in September from a month earlier.

Copper is widely used in manufacturing and construction, and traders watch such data for clues about future demand for the metal.

Investor attention now turns to the third quarter U.S. gross domestic product growth data, due out Friday morning.

Copper settlements (ranges include electronic and pit trading):
Oct $3.5645; down 1.15 cents; Range $3.5550-$3.5875
Dec $3.5505; down 1.75 cents; Range $3.5380-$3.5905