MOSCOW (Reuters) -Rusal said on Monday it had filed a lawsuit in London alleging that Vladimir Potanin, CEO of Nornickel, is in breach of a decade-old deal, renewing a row between two of Russia’s largest metals companies. Rusal said that the lawsuit filed in London’s High Court of Justice on Oct. 21 against Potanin and his affiliate Whiteleave Holdings Ltd is aimed at protecting the interests of Nornickel’s shareholders, adding that no hearing date had been set. A spokesman for Potanin’s holding company Interros, which owns 36% of Nornickel, said his team was reviewing the information in the l…