Several factors combined to send prices falling across the different markets.

Citigroup Inc.'s announcement Sunday that it sees another $8 billion to $11 billion in additional writeoffs due to credit-related losses raised concerns that the fallout from the summer's credit market turmoil has not ended. The announcement accompanied the ouster of chairman and chief executive Charles Prince on Sunday.

Wall Street pulled back in response to the credit concerns Monday, and that was a contributor to the decline in commodities as investors shied away from riskier investments.

"The myriad of banks confessing to write-downs, no doubt, is contributing to an air of anxiety in the financial markets, while increasing the odds of a possible U.S.-led recession being triggered," said MF Global analyst Edward Meir, in a report.

A stronger-than-expected reading on service sector growth Monday helped stem the losses in the commodity and equity markets. The Institute for Supply Management, a private research group, on Monday said its index gauging the health of non-manufacturing industries registered 55.8 in October, up from 54.8 in September and above analysts' consensus forecast.

Gold also got a boost from a recovery in the dollar. The contract for December delivery dropped $1.70 to $806.80 an ounce on the New York Mercantile Exchange, as energy prices dipped and the greenback rebounded from its lows against the euro -- signals that inflation could be easing temporarily. Investors often turn to gold as a hedge against inflation and pull back when the dollar gains strength and oil prices retreat.

Gold last touched $800 in 1980.

A healthier greenback renders commodities a less attractive investment, particularly for buyers abroad. The dollar's rebound was slight, however, and followed a fresh low against the euro. The 13-nation currency bought a record $1.4524 in earlier trading before falling back.

Light, sweet crude for December delivery fell $1.34 to $94.59 a barrel on the Nymex, retreating from a record settlement above $95 a barrel on Friday. Oil is approaching the inflation-adjusted high it reached in 1980, when a barrel cost $38, or $96 to $103 in today's dollars.

Elsewhere on the Nymex, December gasoline futures shed 3.65 cents to $2.403 a gallon, while December heating oil futures declined 2.17 cents to $2.552 a gallon. Silver for December delivery rose 0.6 cent to $14.605 an ounce.

Base metals moved mostly lower on the London Metal Exchange, with nickel, copper, zinc and lead prices all on the decline. December copper futures on the Nymex slipped 0.1 cent to $3.324 a pound.

Agriculture futures were narrowly mixed on the Chicago Board of Trade. December wheat rose 2.5 cents to $7.81 a bushel, while December corn lost 1.75 cents to $3.7525 a bushel. Soybeans for January delivery dipped 0.75 cent to $10.16 a bushel.