Metals ended the week lower Friday on doubts that European authorities will be able to contain that region's financial crisis.

Copper for December delivery fell 2.4 cents, or nearly 1 percent, to close at $3.5645 per pound. It ended the week down 4 percent. Other metals also ended the week lower.

Gold was the lone exception. Gold prices often rise during times of economic turmoil. Gold for December delivery fell $9, or less than 1 percent, to settle at $1,756.10 per ounce. It's still up 1 percent for the week.

Metals rallied last month on news that European finance ministers had crafted a plan to contain that region's financial crisis. But uncertainty returned this week because of political turmoil in Greece.

Greek prime minister George Papandreou said early in the week that Greece would hold a vote to determine if it would abide by the terms of the bailout. He later reversed course and cancelled the referendum, but the political instability raised doubts about the effectiveness of any broad European rescue package.

Also Friday, a summit of the world's wealthiest nations ended without a pledge to lend Europe a hand. Investors had hoped that the Group of 20 summit would end with a promise by nations to help indebted European countries like Greece and Italy. G-20 leaders said Europe needs to help itself first.

December silver fell 41.4 cents, or 1.2 percent, to close at $34.084 an ounce. That leaves silver down 3.3 percent for the week.

December palladium lost $6.80, or 1 percent, to close at $655.30 an ounce, leaving it down 1.6 percent for the week. January platinum dropped $17.70 to finish at $1,629.30 an ounce. Platinum is down nearly 1 percent for the week.

Crop prices were up, with the exception of soybeans. December wheat gained 0.75 cents to finish at $6.3675 per bushel. December corn rose 2.25 cents to end at $6.5575 per bushel. November soybeans lost 6.25 cents to finish at $12.21 a bushel.

Benchmark crude oil gained 19 cents to end at $94.26 per barrel on the New York Mercantile Exchange. That leaves oil up 1 percent for the week.

Heating oil rose 3.26 cents to finish at $3.0707 per gallon, gasoline futures rose 2.16 cents to close at $2.6634 per gallon and natural gas lost 0.9 cents to close at $3.892 per 1,000 cubic feet.