China, the world's biggest producer and consumer of aluminium, churned out 2.97 million tonnes of the metal last month, up 2.3% year-on-year, the National Bureau of Statistics said. First-quarter output was up 2.7% at 8.84 million tonnes.

However, on a daily basis, March output was about 95,800 tonnes, according to Reuters calculations, down from 97,450 tonnes over January and February combined and the lowest daily rate since October.

The bureau does not typically release industrial output data for January and February individually due to the distortion of Lunar New Year.

Aluminium demand in China collapsed as a result of the coronavirus outbreak, with Chinese aluminium processors short-staffed and slow to return to work after containment measures extended the Lunar New Year holiday into February.

Coupled with a broad selloff in commodities from panicked investors, this pushed Shanghai aluminium prices to as low as 11,255 yuan ($1,591.15) a tonne in March, the lowest since early 2016, leading smelters to put production lines into maintenance to avoid losses.

As of April 16, 533,700 tonnes of annual aluminium production in China had been cut so far this year, while smelters have decided to reduce output by another 207,000 tonnes, said Zhang Rufeng, an analyst at consultancy Baiinfo.

China has around 36 million tonnes of annual aluminium smelting capacity.

Aluminium prices hit a fresh four-year low of 11,230 yuan on April 2 but have since recovered to over 12,000 yuan.

"Based on cash costs, 40-50% of smelters are losing money" at current prices levels, Zhang estimated, speaking after the data release.

A slump in the price of raw material alumina , also to the lowest since 2016, is easing some of the pressure on smelters. Prices had initially spiked amid the coronavirus outbreak as bauxite mine closures and logistical problems saw alumina refineries reduce supply.

China's output of 10 nonferrous metals - including copper, aluminium, lead, zinc and nickel ? rose 1.6% year-on-year to 4.83 million tonnes in March but that was the lowest monthly total since May 2019.

First-quarter output was up 2.1% year-on-year at 14.17 million tonnes. The other non-ferrous metals in this group are tin, antimony, mercury, magnesium and titanium.

($1 = 7.0735 yuan)

By Tom Daly