An eight-day rally in silver prices ended Tuesday as traders wait for the Federal Reserve to deliver its assessment on how the U.S. economy is doing.
Silver fell 4.5 percent, a day after pushing close to $50 an ounce. Other commodities were mixed as oil, copper, wheat and soybeans fell while corn, gasoline and heating oil rose.
The Fed is expected to signal Wednesday that it will allow a $600 billion bond-buying program to end in June as planned. In addition, Chairman Ben Bernanke has scheduled a news conference after the meeting ends.
A strong rally in commodity prices began in late August after Bernanke hinted that the central bank may buy government bonds to help stimulate the economy. The program began in November.
The Fed's low interest rates have kept the dollar's value low as other central banks begin to raise interest rates because of inflation fears. Since commodities are priced in dollars, a weak dollar makes them more of a bargain for buyers who use other currencies.
Investors turn to silver and gold during uncertain economic times because they are considered relatively stable assets.
Silver is a thinly traded market, which means price swings are more exaggerated. Silver is also cheaper than gold so it's more accessible to investors to trade in than gold is.
Spencer Patton, founder and chief investment officer for hedge fund Steel Vine Investments LLC, attributed Tuesday's price drop to investors taking profits because they are uncertain about what Bernanke and the Fed may announce.
Silver for May delivery fell $2.099 to settle at $45.05 an ounce while June gold fell $5.60 to settle at $1,503.50 an ounce.
Other metals were mixed. May copper rose 1.6 cents to settle at $4.319 a pound, July platinum fell $22.70 to $1,805.40 an ounce and June palladium fell $5.10 to $755.70 an ounce.
Corn rose after the U.S. Agriculture Department said about 9 percent of the crop had been planted for the week ending April 24. That compared with 46 percent planted during the comparable week a year ago and 23 percent on average over the past five years.
Farmers have been delayed from getting into the fields by wet, cool weather and flooding, which may affect the number of acres planted this year, analysts have said. Corn supplies are tight globally.
In contracts for July delivery, corn rose 4.25 cents to settle at $7.7275 a bushel, wheat fell 14.25 cents to $8.47 a bushel and soybeans fell 7.25 cents to $13.8925 a bushel.
Benchmark crude for June delivery fell 7 cents to settle at $112.21 per barrel on the New York Mercantile Exchange.
In other Nymex trading, heating oil rose 2.84 cents to settle at $3.2273 per gallon, gasoline rose 2.87 cents to $3.3072 per gallon and natural gas fell 0.2 cent to $4.387 per 1,000 cubic feet.
Associated Press Economics Writer Jeannine Aversa contributed to this report.