NEW YORK — A nine-month rally in oil prices appeared to falter as a gradual sell-off that began in late October gained momentum.

Crude prices declined Friday for the eighth day in a row. The contract for January delivery gave up 67 cents to settle at $69.87 a barrel on the New York Mercantile Exchange. It's the first time that oil has closed below $70 a barrel since early October.

Prices tumbled as the dollar gained strength and investors took a second look at paltry demand figures in the West.