The Dallas Federal Reserve's monthly general business services index fell to a reading of 4.2 in August from 6.6 in July, indicating a slower pace of expansion.
The expectations were for an increase to a reading of 7.2 in a survey compiled by Bloomberg.
There were decreases in the readings for revenue, employment and selling prices. The index for wages and benefits increased.
This is the final regional services reading for the month, most of which have indicated contraction, except New York Fed Services which suggested slower pace of expansion. The S&P Global flash reading suggested a faster pace of expansion.