* Senior judges say appeal has "real prospect of success"
* Claimants' lawyers hail ruling as "monumental judgment"
* BHP says proceedings do not belong in UK
* 2015 dam failure caused Brazil's worst environmentaldisaster
(Adds no comment from Vale)By Kirstin RidleyLONDON, July 27(Reuters) - London's Court of Appeal made aU-turn on Tuesday by agreeing to reopen a $7 billion lawsuit by200,000 claimants against Anglo-Australian mining giant BHP, reviving a case over a dam rupture behindBrazil's worst environmental disaster.Lawyers for one of the largest group claims in English legalhistory have been pushing to resurrect the 5 billion pound ($6.9billion) lawsuit against BHP since a lower court struck out thelawsuit as an abuse of process last year - and a Court of Appealjudge upheld that decision in March.But in a highly unusual move, three Appeal Court judges onTuesday reversed course and granted permission for an appeal,saying they believed it had a "real prospect of success".
The collapse in 2015 of the Fundao dam, owned by the Samarcoventure between BHP and Brazilian iron ore mining giant Vale , killed 19 and obliterated villages as a torrent ofmore than 40 million cubic metres of mining waste swept into theDoce river and Atlantic Ocean over 650 km (400 miles) away.Tom Goodhead, a PGMBM managing partner who is bringing theclaim on behalf of Brazilian individuals, businesses, churches,organisations, municipalities and indigenous people, called it a"monumental judgement".Frederico de Assis Faria, Attorney General of Brazil'shard-hit district of Mariana, said victims now had "anopportunity for real justice" six years after the disaster.BHP, the world's largest mining company by market value, haslabelled the case pointless and wasteful, saying it duplicatesproceedings in Brazil and the work of the Renova Foundation, anentity created by the company and its Brazilian partners tomanage reparations and repairs. "BHP's position remains that the proceedings do not belongin the UK," it said in a statement.Contacted in Brazil, Vale declined comment.
'GOOD DAY FOR JUSTICE'The case was revived after PGMBM in April applied for anoral Court of Appeal hearing - reserved only for exceptionalcases - and argued the appeal judge had not properly grappledwith arguments about why the case should proceed. Martyn Day, the Leigh Day lawyer who has taken on minerVedanta and oil giant Shell in English courts on behalfof villagers over alleged pollution in Zambia and oil spills inthe Niger delta respectively, welcomed the ruling."It is highly unusual for the Court of Appeal to use thismechanism (of an oral hearing) for reviewing a decision of afellow member of the court," he said. "A good day for justice."Claimant lawyers have argued that most of their clients havenot brought proceedings in Brazil, that they are entitled to sueBHP in England and that Brazilian litigation is so lengthy thatit cannot provide full redress in a realistic timeframe.The lawsuit is the latest battle to establish whethermultinationals can be held liable for the conduct of overseassubsidiaries on their home turf.The appeal is expected to be heard next year and any rulingis likely to be further appealed to the Supreme Court in London.
(Reporting by Kirstin Ridley; Editing by Kirsten Donovan andEdmund Blair)