Aurubis spokesman Malte Blombach confirmed its premium initially reported by Fastmarkets on Monday at 10:39am London time.

The offer forms the basis of Aurubis' contracts with copper product customers as well as constituting a delivered cathode premium. At $96 per tonne, the premium is the highest since 2015 when it offered customers a $110 per tonne premium.

The move comes after Chile's state-owned copper producer Codelco also increased its offer to European customers by $10 year on year with a $98 per tonne offer for 2019 supply.

Additional reporting by Julian Luk

[This article was updated to include confirmation of the premium offer from the company.]