U.S. consumer confidence declined more than expected in September amid mounting worries over the availability of jobs.

The Conference Board said on Tuesday its consumer confidence index dropped by 3.6 points to 94.2 this month. Economists polled by Reuters had forecast the index dipping to 96.0.

"Consumers' assessment of business conditions was much less positive than in recent months, while their appraisal of current job availability fell for the ninth straight month to reach a new multi-year low," said Stephanie Guichard, senior economist, global indicators at the Conference Board. This is consistent with the decline in job openings."