China exported 380,000 tonnes of aluminum in semi-fabricated form in April.

It was the highest monthly total since November 2015 and brings the year-to-date tally to 1.33 million tonnes, up two percent on the same period of 2016.

Exports of bars, rods and profiles  have slumped by 34 percent, or 132,000 tonnes, in the first four months of the year.

Exports of plate, sheet and strip, by contrast, have risen by 20 percent, or 105,000 tonnes. Those of foil are up by 14 percent, or 47,000 tonnes.

There should be no doubting Beijing's zeal when it comes to reforming its aluminum sector.

Chinese policy makers are targeting the giant aluminum sector for supply-side reform this year.

A national audit will weed out those that have failed to tick all the legal boxes, while those in the region surrounding Beijing will be forced to cut production by at least 30 percent over the next winter heating season starting November.

Environmental urgency to tackle what is a massive user of coal-fired power is overlaid with diplomatic urgency to preempt a trade showdown.

Uncertainty over future production in China, which produces more than half the world's aluminum, is the single most important reason why the London metal price is up 14.5 percent this year, outstripping all the other major industrial metals.(Abirdged)