US producer prices fell in April after a small rise March, returning to a months-long slide in a weak start to the second quarter, Labor Department data published Thursday showed.

The producer price index unexpectedly fell 0.4 percent, led by a sharp 2.9 percent drop in energy costs as gasoline prices slid 4.7 percent.

Pipeline inflationary pressures resumed their downward trajectory after a 0.2 percent rise in PPI in March, the first increase since last October.

Food prices fell 0.9 percent in April.

Analysts had estimated PPI would rise 0.2 percent for the second straight month.

Stripping out food and energy, core PPI fell 0.2 percent and was up a modest 0.8 percent from a year ago.

On a year-over-year basis, producer prices fell 1.3 percent.

"There are no pricing pressures down the producer pipeline. This should keep both consumer and producer price growth in check," said Briefing.com.