(Updates with Samarco comments)

SAO PAULO, July 16 (Reuters) – Creditors in bankrupt miner Samarco Mineracao SA, a joint venture between Vale SA and BHP Group PLC, objected to the company's restructuring plan on Thursday, according to a court document.

Creditors said the plan's main goal is to protect Samarco's giant shareholders, Vale and BHP, and reduce future payments to creditors.

They also rejected Samarco's offer to apply an 85% haircut to all creditors, including shareholders Vale and BHP, which extended 24 billion reais in loans to the company. Payments would occur in 2041.

Creditors said both Vale and BHP, as shareholders, should be paid only after all other creditors fully recover their money. They also questioned if both giant companies should recover any value as creditors consider that both miners are co-debtors.

They also refused Samarco's offer to swap their debt into shares in the company.

"It is unacceptable that a restructuring plan of a company controlled by the world's biggest miners outlines an outright (and illegal) debt forgiveness to create value for its multimillionaire shareholders, which are also responsible for Brazil's biggest environmental disaster," creditors said in the court document.

The collapse of a dam at the Samarco mine complex in 2015 killed 19 people, severely polluted the Doce River with mining waste and led the company into financial trouble.

Creditors have proposed Samarco, Vale and BHP pay in three equal parts for all damage caused by the rupture of the dam, creditors lawyers Paulo Padis and Marcos Pitanga said in an interview. That contrasts with Samarco's restructuring plan, which proposes the company pay for the damage entirely.

Both creditors and Samarco said they have recently signed confidentiality deals to start negotiations.

Samarco said in a statement that the proposed restructuring plan takes into consideration the company's financials and aims at keeping payments to repair damage caused by the disaster. It added creditors have not presented any alternative plan so far.

(Reporting by Carolina Mandl; Editing by Sam Holmes and Nick Macfie)