LONDON - A London court on Friday rejected BHP Group's request to delay until mid-2025 a potential 36-billion pound ($44-billion) lawsuit over Brazil's worst environmental disaster, instead granting a five-month deferral.

The world's biggest miner by market value is being sued by 720 000 Brazilians over the 2015 collapse of the Fundao dam owned by the Samarco joint venture BHP holds with Brazilian iron ore producer Vale.

When the dam collapsed, 19 people were killed as mud and toxic mining waste swept into the Doce river, obliterating villages, contaminating water supplies and reaching the Atlantic Ocean more than 650 km away.

BHP said in an email on Friday "it denies the claims brought in the UK in their entirety and will continue to defend the case".

The company was initially being sued by around 200 000 people but in March the number of claimants leapt by 500 000.

BHP's lawyers had said the April 2024 trial should be delayed until at least June 2025 to give the company more time to prepare and allow Vale to participate.

But Judge Finola O'Farrell on Friday set a trial start date of October 7, 2024 and said "this will give the parties a more relaxed, achievable timetable and will provide time for Vale and others to participate if necessary."

BHP applied in December to have Vale join the case.

Vale has challenged the London High Court's jurisdiction to determine the claim, and that challenge will be heard in July.

Reparation and compensation programmes implemented by the Renova Foundation, a redress scheme established in 2016 by Samarco and its shareholders, in connection with the disaster had funded $6 billion in financial aid as of the end of 2022, BHP said.

The lawsuit, one of the largest in English legal history, first began in 2018 and was thrown out of court two years later, before the Court of Appeal ruled in July that it could proceed.

"Over seven years on from the disaster, today's Judgment means our clients will finally have their day in court and they are now one step closer to the justice they deserve," Tom Goodhead of law firm Pogust Goodhead, which represents the claimants, said in a statement.

BHP has also applied to the Supreme Court to end the case without trial following the Court of Appeal's decision last year.