Analysts in a Reuters poll had forecast a 0.6 percent increase. Of the 21 major commodity groups, prices rose in seven, fell in eight and were unchanged in six.
Prices for energy and petroleum products posted a 5.5 percent gain, the largest month-on-month jump since May 2016, pushed up by higher gasoline prices. Chemicals and chemical product prices edged up by 0.4 percent.
Prices for motorized and recreational vehicles fell by 0.7 percent, largely due to a 0.8 percent increase in the Canadian dollar against the greenback in December. Many vehicles are priced in U.S. dollars and become less expensive when the Canadian currency strengthens.
Raw material prices climbed by 6.5 percent from November, boosted by higher prices for crude energy products.
(Reporting by David Ljunggren; Editing by Meredith Mazzilli)
