NEW YORK, Oct 21: Gold fell back from $600/oz Friday, shadowing the decline in oil prices amid doubts about Opec's pledge to cut 1.2 million barrels a day in output.

Copper fell on pre-weekend liquidation and the possibility of quick contract negotiations at a Chilean mine.

In agricultural markets, wheat ended mixed for a second straight day, corn turned weak and soybeans hit the brakes on a powerful rally from earlier in the week.

Arabica coffee rebounded after two days of losses while sugar ended up and cocoa down, both in quiet trade.

Orange juice futures finished higher on switch trade as themarket was buoyed again by the speculative fever that took it to 16-year tops this week. Cotton closed down in featureless trade.

The Reuters/Jefferies CRB Index, a composite of 19 commodity futures prices, fell 0.72 per cent to 305.74.

The Goldman Sachs Commodity Index, which also tracks futures prices but is more energy-weighted, slid 1.03 per cent to 5,813.47.—Reuters