LONDON, July 3 (Reuters) - The London Metal Exchange (LME) will suspend the listing of a nickel brand produced by a plant in Finland owned by Russian metals giant Nornickel , it said on Wednesday, without providing a reason for the suspension.

The decision by the LME, the world's largest and oldest metals trading venue, is related to its responsible sourcing campaign, rather than Russia-related sanctions, two sources familiar with the matter told Reuters.

The LME declined to comment. Nornickel did not reply to a Reuters request for comment.

Deliveries of nickel cathodes and briquettes produced by Norilsk Nickel Harjavalta Oy will not be accepted for the LME nickel contract warranting from Oct. 3, the LME said in two separate notices.

The LME, owned by Hong Kong Exchanges and Clearing , said in January it would suspend or delist 10% of its listed metals brands until their producers provided it with their responsible sourcing reports.

Harjavalta, one of the largest nickel refining plants in Europe, is yet to complete its routine responsible minerals audit, one of the sources said, adding that the process was likely to be completed before the LME's Oct. 3 deadline.

The plant has an annual production capacity of 65,000 metric tons of nickel which it produces from raw materials of Russian or other origin. Nornickel itself produced 209,000 tons of nickel in 2023.

The LME in April banned from its system all Russian aluminium, copper and nickel produced from April 13 to comply with U.S. and UK sanctions imposed over Russia's 2022 invasion of Ukraine.

Nornickel's Finnish plant was unaffected by that decision. (Reporting by Polina Devitt; Editing by Jan Harvey)