(This Oct. 9 story has been corrected to remove a reference to BlackRock as they are not part of this deal, in paragraph 7)

Indigenous organizations in the Brazilian state of Para said they were not consulted by the government before it signed a deal with multinational companies to sell carbon offset credits to support conservation of the Amazon rainforest in the state.

Amazon.com Inc (AMZN.O)and other firms agreed last month to buy carbon credits valued at $180 million through the LEAF Coalition conservation initiative, which it helped set up in 2021 with a group of companies and governments, including the United States and United Kingdom.

At the time, Para Governor Helder Barbalho said the deal had the participation of Indigenous peoples and traditional communities.

But on Tuesday, 38 Indigenous and community organizations from Para signed a public letter denouncing his failure to consult them.

"It is unacceptable for the government of Para to take decisions without consulting traditional communities, who are the greatest protectors of the forests while also being the most impacted by the lack of effective climate adaptation policies," they said in the letter.

"Forest peoples must be heard and consulted. Our territories are not for sale," they said.

Alessandra Korap Munduruku, a tribal leader who was the letter's principal author, said the role of U.S.-based companies like Amazon and Walmart (WMT.N),ian the carbon credit purchase was worrying.

"Our priority is the eviction of invaders on our reservation lands that are threatened by miners and a grain railway," she told Reuters by telephone. "Our leaders were never consulted on the carbon credits. We are being sold like goods."

The governor's office did not immediately reply to a request for comment.

Korap Munduruku is an Indigenous teacher turned community leader who won the prestigious Goldman environmental prize in 2023 for her efforts to convince mining companies leave Munduruku lands.

The agreement is LEAF's first deal in the Amazon, the world's largest rainforest, which is vital to curbing climate change because of the enormous amount of greenhouse gas its trees absorb.

The deal foresees the purchase of up to 12 million tons of carbon credits generated by reducing deforestation in Para between 2023 and 2026. It was announced on Sept. 24 during New York Climate Week.

Each of the credits represents a reduction of 1 metric ton of carbon emissions and they are jurisdictional, so Para gets paid for reducing deforestation across the state, including on public lands like reservations.

Governor Barbalho said the state would only collect the portion of the sales' proceeds needed to continue its efforts to cut greenhouse gas emissions, while the rest would go to Indigenous peoples and traditional communities as well as family farms.

Para will host the UN COP30 climate summit next year, in a move that is the centerpiece of President Luiz Inacio Lula da Silva's bid to restore Brazil's environmental credentials after years of soaring deforestation.