BHP Billiton has reached a near $A1 billion deal with Brazil's federal prosecutor to settle a civil claim over the fatal disaster at its Samarco joint venture.

Under the preliminary agreement, BHP, its joint venture partner Vale, and Samarco will pay approximately $US675 million ($A898 million) to support social and environmental programs, and another $US60 million ($A80 million) to local municipalities.

The agreement, which is subject to court approval, is a response to a civil claim for $US47.5 billion ($A63.2 billion).

BHP said the resumption of operations at Samarco, where 19 people died in a November 2015 dam disaster, was not part of the agreement and subject to separate negotiations.

It said the mine will only reopen if it is safe and economically viable.

Operations at the Samarco mine have been suspended since the fatal tailings dam disaster that killed 19 people and led to widespread environmental damage.