Court papers noted that Nautilus had two distinct business units, one dealing with polymetallic nodules, and one dealing with seafloor massive sulphides.
Vale said its annual assets review of its base metals and coal business is still underway and further impairments charges that would also impact fiscal year 2019 cannot be ruled out.
Ethical investors plan to extend their campaign for miners and other big businesses to stop funding industry associations that block progress on UN goals to curb climate change.