Stock futures slightly trimmed losses but still pointed to a steep drop at the open on Monday after a regional gauge of manufacturing suggested growth was returning to the sector.

The New York Federal Reserve said in a report a measure of manufacturing in New York state moved into positive territory. It was the highest reading since November 2007.

Even so, U.S. stocks were set for deep fall at the open, as investors worried the recent global equities advance outpaced the prospects of an economic recovery.

S&P 500 futures slid 18.9 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures tumbled 160 points, and Nasdaq 100 futures were down 27 points.

(Editing by Padraic Cassidy)