MOSCOW – Russian businessman Vladimir Potanin plans to appeal a London court decision to block him from buying shares in mining company Norilsk Nickel from fellow investor Roman Abramovich, representatives at Potanin's investment firm said on Tuesday.

The ruling, taken in June, was considered to be advantageous for Russian tycoon Oleg Deripaska, who controls aluminium giant Rusal, and has long been at loggerheads with Potanin over control of Norilsk Nickel.

He wanted to stop Abramovich, owner of England's Chelsea soccer club, from selling shares in the company to Potanin, saying that would violate a 2012 shareholder agreement.

Representatives of Interros, which manages Potanin's assets, said they had filed a request together with Abramovich's investment vehicle Crispian, to be allowed to appeal the decision.

"Today the judge satisfied our request," Interros said. "Within 21 days after receipt of the court decision we have to submit our appeal to London's Court of Appeal."

Rusal, which holds a 27.8% stake in Nornickel, declined to comment. A representative for Abramovich did not respond to requests for comment.

In September, Potanin returned a 2% stake in Nornickel to Abramovich and his partners, that he had previously bought from them for about $800-million - a move which had increased his holding in the miner to 32.9%.

He had previously promised to return the stake to Abramovich if the London court ruled against the deal.

Deripaska and Potanin have battled over control of Nornickel ever since Rusal, the world's largest aluminium producer outside China, bought a stake in the miner just before the 2008 global financial crash.

Abramovich stepped in as a "white knight" minority shareholder in 2012 to act as a buffer between Potanin and Deripaska.

The long-running conflict was overshadowed in April this year by US sanctions imposed against Deripaska and some of his companies, including Rusal.

Nornickel competes with Brazil's Vale for the rank of the world's top nickel producer and is also the world's largest palladium producer.