Norilsk Nickel was named in a 4.35 billion ruble ($178 million) pollution lawsuit filed by the Natural Resources Ministry's environmental watchdog on Wednesday in its largest-ever claim against a metals company...Stemming from the alleged pollution of rivers in Siberia, the environmental watchdog said its deputy head, Oleg Mitvol, had lodged the claim with the Krasnoyarsk regional arbitration court...The company disputed the agency's findings. "We are going to appeal," a company spokeswoman said [also refers to Shell, Gazprom, RusAl, Baikal Pulp and Paper Mill, Eurasian Energy Company (part of Evraz Group)].