LONDON - US-based aluminium producer Alcoa supports an idea proposed last week by Russian producer Rusal for the London Metal Exchange to provide details about the origin of all metal in LME approved warehouses.

Aluminium producer Rusal and Russian metal have not been directly targeted by sanctions imposed on Russia after it invaded Ukraine in February.

But Alcoa has actively campaigned to ban Russian metal from being traded and stored on the LME. It is concerned that large amounts of aluminium in the LME system could distort pricing.

The LME after an industry consultation in October decided there would be no boycott of Russian metal as a significant portion of the market was still planning to buy it next year.

Instead, the world's largest and oldest forum for trading metals said it will publish regular reports from January 2023 detailing the percentage of Russian metal stored under warrant in LME warehouses to provide transparency.

But Rusal has called for the LME to start regularly disclosing the origin of all metal stocks on warrant rather than singling out Russian metal.

Alcoa said in an emailed statement to Reuters: "We support proposals that would provide market participants with more data, including monthly reports that would disclose the origin of all metal stocks on warrant."

"The important issue at present is to ensure that the market has increased visibility on Russian-origin aluminum, which will allow both the LME and market participants to carefully monitor this situation."

The LME last week said it was considering the format of the monthly report it intends to publish and will work to ensure this best meets the need of all stakeholders.

Rusal is the world's largest aluminium producer outside China accounting for 6% of global supplies estimated at around 70-million tonnes this year. Banning its metal from the exchange could create a price surge, benefiting other producers.

Rusal has consistently denied it would deliver aluminium to LME warehouses. Data from the exchange shows Russian aluminium in LME warehouses at just 17.7% of the total at 586,225 tonnes as of October 28.

Over the weekend, Rusal told Reuters its sales had already exceeded 76% of its primary aluminium and value added production for 2023, confirming an earlier source-based Reuters report.

Other producers have also publicly called for a ban on Russian metal.

Alcoa is also lobbying for a US ban on Russian aluminium imports.