The August Manufacturing Business Outlook Survey indicated the manufacturing sector in some eastern U.S. states experienced slower growth, the Federal Reserve Bank of Philadelphia reported on Thursday.

The survey, conducted by the Federal Reserve Bank of Philadelphia which is responsible for the Third District covering eastern Pennsylvania, southern New Jersey, and Delaware, suggested that the region's manufacturing sector experienced slower growth in August.

The diffusion index for current general activity decreased 14 points this month to 11.9, its lowest reading in 21 months. Nearly 32 percent of the manufacturers reported increases in overall activity this month, while 20 percent reported decreases.

The new orders index fell 22 points to 9.9.

The firms continued to report overall higher employment, but increases were less widespread this month. The current employment index fell 3 points to 14.3. The current average workweek index declined 3 points.

Looking ahead six months, however, the firms remain optimistic, and most of the future indicators showed improvement.

The Manufacturing Business Outlook Survey is a monthly survey of manufacturers in the Third Federal Reserve District. Participants indicate the direction of change in overall business activity and in the various measures of activity at their plants.

Federal Reserve Bank of Philadelphia is one of the 12 regional Federal Reserve Banks that, together with the Board of Governors based in Washington D.C., make up the Federal Reserve System.