LONDON—London’s Court of Appeal will hear a request to revive a 5 billion pound ($6.95 billion) lawsuit against Anglo-Australian mining group BHP over a 2015 dam failure in Brazil, a court order showed. Judge Nicholas Underhill has agreed to an oral hearing that could help to overturn a previous Court of Appeal decision which denied a 200,000-strong Brazilian claimant group permission to appeal against a judgment to strike out the landmark case. “I am satisfied that, exceptionally, an oral hearing is appropriate in this case,” the judge said in the order, which was signed on May 4 and seen by Reuters on Thursday. No further details were immediately available. The order comes less than two months after the Court of Appeal refused permission for a lawsuit over Brazil’s worst environmental disaster to proceed in English courts. The Court of Appeal said in March it agreed with a lower court that …