Prices paid to U.S. producers slipped 0.1% in December, the Labor Department said Wednesday.
The so-called core producer price index excluding food and energy rose 0.3%, Labor said.
Analysts had projected that both the PPI and core prices would edge up 0.1%, Bloomberg reported.
Wholesale prices rose 4.8% last year, the largest gain since 2007, while the core index rose 3%.
An increase in the PPI could indicate strong demand for goods, which would mean more shipments for trucking companies. However, if inflation begins to accelerate too quickly, it could also hurt the economy.