Wholesale prices rose less than expected in December, a positive sign for the economy amid recent market fears that inflation isn't falling as quickly as hoped to the Federal Reserve's 2% target.

U.S. producer prices rose less than expected in December as higher costs for goods were partially offset by stable services prices, suggesting inflation remained on a downward trend after progress had stalled in recent months.

Where prices did climb — warehousing and transportation — points to an inventory build. Upcoming CPI will make the inflation picture clearer.