The Consumer Confidence Index dived to 80.3 in December from a revised 84.9 in November, according to data from an influential business lobby group, the Conference Board

The figure was in stark contrast to analysts' forecasts of a slight rise to 85.5, and was the sixth fall in the past seven months.

"The major factor dampening consumers' spirits has been the rising unemployment rate and the discouraging job outlook," said a Conference Board spokeswoman.