The U.S. Bureau of Labor Statistics said its producer price index, which measures wholesale prices, rose 0.2% percent in July, seasonally adjusted, with the so-called core index, which exempts food and energy costs, up 0.4%, its eighth straight month of increase.

The gain follows a 0.4% decrease in June and a 0.2% rise in May. On an unadjusted basis, prices for finished goods moved up 7.2% for the 12 months ended July 2011.

At the earlier stages of processing, prices received by manufacturers of intermediate goods moved up 0.2% in July, and the crude goods index declined 1.2%.

Analysts have been watching the index as any significant rise makes it more difficult for the Federal Reserve to ease credit.