Washington (AFP) - US wholesale inflation continued its upward trend in January, recording its largest monthly gain in more than four years, according to data released Tuesday by the Labor Department.

The Producer Price Index, which measures prices from the seller's perspective, rose 0.6 percent in seasonally adjusted figures, which was the largest such gain since September 2012 and well above an analyst consensus forecast of 0.3 percent.

Excluding food and energy, the index saw a monthly gain of 0.4 percent.

Year over year, however, the figure was unchanged at 1.6 percent, unadjusted.

"In short, fairly strong and not just because of energy," Jim O'Sullivan, chief US economist at High Frequency Economics, wrote in a client note.

"The core measures continue to show some acceleration, even if the latest data were exaggerated a bit by volatile trade margins."

The large month-to-month gain supports views among US monetary policymakers that further interest rate increases may be necessary in 2017 to contain inflation. The central bank earlier this month left interest rates unchanged after raising them in December for the first time in a year.

The Federal Reserve during most of 2016 refrained from raising rates too quickly for fear of interrupting a fragile recovery but has taken a different view of the likely course of monetary policy in 2017, citing "uncertainty" as any expansionary fiscal policies from President Donald Trump's have yet to take shape -- despite promises of infrastructure spending, slashed taxes and regulation.

Tuesday's Labor Department figures also showed that upward price pressures were less apparent when the more volatile categories of food, fuel and trade were excluded.

By this measure, prices rose only 0.2 percent in January, up a tenth of a point from December but matching November's increase. For the year, the measure rose only 1.6 percent, down a tenth from the result recorded in December.