Of the 21 major commodity groups tracked by the agency, 17 rose, three fell and one was unchanged.

Prices for energy and petroleum products fell by 6.6 percent, the greatest month-over-month drop since the 7.5 percent decline recorded in January 2016. Gas prices plummeted by 10.7 percent, the biggest plunge since the 12.0 percent seen in January 2015.

Prices for chemicals and chemical products slipped by 1.6 percent on weaker demand for petrochemicals.

Raw materials prices fell 11.7 percent, the largest drop in at least eight years, on lower price for crude energy products amid a global supply glut.

(Reporting by David Ljunggren; Editing by Steve Orlofsky)