American manufacturing slowed for a fourth straight month in November in its worst performance since June, according to a survey of manufacturers released Friday.

The National Association of Purchasing Management said U.S. factory output declined at a slightly faster rate than in October. Economists said the report suggested manufacturing remains sluggish.

In its monthly report, the NAPM said its index of manufacturing growth slipped to 46.5 percent in November from 46.8 percent in October.

An index reading above 50 percent indicates an expansion of activity at the nation’s factories, while a reading below 50 percent indicates a decline. Financial markets watch the number closely as a barometer of the economy’s strength.

November’s reading was the lowest reading since June, when it was 44.8 percent. The index has remained at less than 50 percent since falling to 46.9 percent in August.

NAPM’s new orders index rose to 50.1 percent from 48.1 percent in October. But its production index fell to 45.8 percent from 48.2 percent, the lowest rate since June, when it was 44.8 percent.

The employment index fell for the ninth straight month to 44.1 percent from 45.2 percent.