Gold and other metals extended recent losses Wednesday as the dollar rose for the fifth straight day.
Gold for December delivery lost $4.90 to $1,030.50 an ounce on the New York Mercantile Exchange _ its lowest close in nearly a month. Gold prices have fallen about $30 over the past week as the dollar puts in its longest winning streak since early July.
The ICE Futures US dollar index, a widely used measure of the dollar's value against other currencies, gained 0.4 percent in afternoon trading.
A stronger dollar often drives selloffs in commodities as they become more expensive for buyers outside the U.S.
Commodities have rallied this year on the back of a weaker dollar, as record-low interest rates and an improving outlook on the economy drives investors to park their cash in riskier assets.
Many analysts believe the dollar will continue to weaken over the long term, so long as interest rates remain low. But in the near term, the dollar may show more strength, meaning commodities prices could have further to fall.
"I think the rally in the dollar could have some room to run, albeit temporarily," said Matt Zeman, head trader at LaSalle Futures in Chicago. "So long as the dollar stays strong we're going to see weakness across the board."
Among other metals, December silver tumbled 30 cents to $16.24 an ounce, while October platinum dropped $15.30 to $1,297.40 an ounce. Palladium fell 4 percent.
December copper futures fell 6.85 cents to $2.9305 a pound.
Elsewhere on the Nymex, energy prices fell sharply after the Energy Department said gasoline supplies rose by nearly 2 million barrels last week. Many energy analysts had expected supplies to fall for a third week in a row.
Gasoline for November delivery dropped 8.41 cents, or 4.1 percent, to $1.9864 a gallon.
Light, sweet crude for December delivery fell $2.09, or more than 2 percent, to settle at $77.46 a barrel, and heating oil fell 5.82 cents to settle at $1.9969 a gallon.
On the Chicago Board of Trade, December wheat futures gave up 8.5 cents to $4.9475 a bushel, while corn for December delivery slipped 1.75 cents to $3.69 a bushel.
January soybeans shed 6 cents to $9.705 a bushel.
Other soft commodities, including cocoa, sugar and cotton, also fell.