Brazil files $43.5bn claim over fatal dam disaster
Federal prosecutors in Brazil have filed a $43.5bn (£30bn) civil lawsuit against iron miner Samarco, and its owners BHP Billiton and Vale.
It follows the collapse of a dam they owned that caused a huge mudslide, polluted a river, and killed 19 people.
Anglo-Australian BHP and Brazil's Vale said they had yet to receive formal notice of the claim.
BHP's Australia-listed shares had fallen more than 9% by the end of the trading session.
In a statement, BHP said: "BHP Billiton remains committed to helping Samarco to rebuild the community and restore the environment affected by the failure of the dam."
In their 359-page lawsuit, prosecutors said they used the BP oil rig disaster in the Gulf of Mexico to help assess the likely costs and compensation.
BP's total pre-tax charge for that spill has reached more than $55bn.
The civil action is separate from a lawsuit that Samarco, Vale and BHP settled with Brazil's government in March, in which the companies agreed to pay an estimated 20bn Brazilian reais (£3.86bn) for the damage.
Federal and state prosecutors did not form part of that settlement.
The Bloomberg news agency, which first reported the lawsuit, said prosecutors were demanding an initial payment of 7.8bn reais within 30 days.