A fresh legal broadside has opened in the dispute between the Russian oligarch owner of Aughinish Alumina and his business partners. Oleg Deripaska, the controversial, sanctioned oligarch; his company Rusal, which owns the Limerick alumina plant; and EN+ Group, the overall parent, are being sued by two of its shareholders in the UK in a fractious dispute between the sides going back well over a decade. Entities connected with Rusal shareholders Viktor Vekselberg and Len Blavatnik filed their action in London’s commercial court this week. The first, SUAL Partners, is an investment vehicle of Vekselberg’s, a Russian oligarch sanctioned by…