The U.S. economy’s services sector grew in September, but at a much slower pace than in August, amid a sharp rise in energy costs.

The Institute of Supply Management said today its non-manufacturing business activity index was at 53.3 in September, down from August’s reading of 65.

Any number above 50 indicates growth.

The group’s index of prices paid rose 14.3 points to 81.4.

The survey found that many business executives are concerned about the continuing rise in oil and gas prices after Hurricane Katrina and the toll rising energy costs will take on the economy.