Confidence among U.S. consumers rose for a second month in August, the first back-to-back gains in almost two years and a sign that Americans are heartened by lower energy costs, Bloomberg reported.

The Reuters/University of Michigan preliminary index of consumer sentiment increased to 61.7, less than forecast, from 61.2 in July. The measure averaged 85.6 in 2007.

Declining gasoline prices may prevent further erosion in consumer spending, the biggest part of the U.S. economy, as Americans face a weakening labor market and the worst housing market in 26 years, Bloomberg said.

The survey also found that consumers expect the inflation rate over the next five years to be 3.2 percent, unchanged from last month.

Economists had forecast the confidence index would rise to 62, according to the median of 64 projections in a Bloomberg News survey. Estimates ranged from 56 to 69.

The Federal Reserve today said U.S. industrial production rose in July, boosted by gains in automobiles, metals and machinery.

Consumers polled by Reuters/University of Michigan said they expect an inflation rate of 4.8 percent over the next 12 months, down from a 5.1 percent forecast in the July survey.

The cost of living was up 5.6 percent in the year ended July 31, the biggest jump in 17 years, the U.S. Labor Department said Thursday. So-called core prices, which exclude food and energy, also rose more than projected.