US industry surged back to life in 2017, posting the biggest increase in output in seven years, with the largest gain in the mining sector, the Federal Reserve said Wednesday.

Industrial production rose 3.6 percent for the year on an 11.5 percent surge in mining activity, the biggest gain for that sector since 2014.

The vital manufacturing sector posted its largest increase in six years, rising 2.4 percent, the Fed said in the monthly report.

For the final month of the year, total output rebounded 0.9 percent compared to November, on a large jump in utilities, far stronger than even the most optimistic analysts were expecting.

But the December increase came after the November result was revised to show a slight decline instead of a slight increase, according to the Fed data.

The monthly rise included a 1.6 gain in mining, attributed primarily to oil and gas extraction, and a 0.1 percent rise in manufacturing output, its fourth consecutive increase.

The fourth quarter was particularly strong, jumping 8.2 percent, after back-to-back Hurricanes Harvey and Irma disrupted industrial activity in the prior quarter.

For all of 2017, the gains were broad-based, with only a few categories showing declines.

The biggest gains were in machinery, plastics and metal products, with a tepid 0.4 percent rise in motor vehicles and part.

The largest declines were in clothing, paper products, appliances and furniture.

Total industrial capacity in use in the final month of the year was at 77.9 percent, which is an increase of 1.1 points over December 2016, the report said.

But the manufacturing sector still shows a higher rate of idle capacity and at 76.4 percent it is running two points below its long-run average.

Source:AFP