Rusal, the world's largest aluminum producer outside China, is expected to account for 6% of global supplies of the metal this year.

Also undermining copper was news of a possible labor deal in a mandatory mediation process to avoid a strike at Los Pelambres.

The smelter produces around 165,000 tonnes of zinc and zinc alloys per year, according to its website.

Weaker smelting activity in China was mainly behind the lackluster readings.

What will happen to Russian metal is one of the hottest topics of debate among traders.

Talks formally begin on Wednesday.

Production from state-owned giant Codelco fell 29.6% on a year-on-year basis.