Amnesty International and other rights groups on Monday called on Nigeria's government to halt a deal for Shell to sell some of its assets as a way to guarantee rights of local communities.

Farming and fishing communities in the Niger Delta, the heartland of Nigeria's crude production, have fought years of legal battles over damage from oil spills in the area.

Shell has agreed to sell its onshore assets in the country to a Nigeria-based group for up to $2.4 billion as it shifts to offshore operations.

In an open letter released on Monday, Amnesty and dozens of other Nigerian and international rights groups called on a Nigeria regulatory commission to refuse approval of the sale of Shell assets to Renaissance African Energy.

"Shell should not be permitted to use legal gymnastics to escape its responsibilities for cleaning up its widespread legacy of pollution," the letter said.

It added that the sale of Shell assets should not be permitted unless local communities have been fully consulted, the environmental pollution caused to date fully assessed and funds made available to cover clean-up costs.

Shell did not immediately respond to a request for comment.

Oil companies generally say they operate according to the sector's environmental best practices and blame most spills on sabotage and oil thieves tapping into pipelines.

Britain's Supreme Court ruled recently it was too late for a group of Nigerians to sue Shell over a 2011 offshore oil spill. But the company faces other legal challenges over spills.

Nigeria, Africa's top economy and major oil producer, wants to attract more foreign investment since President Bola Ahmed Tinubu came to office in 2023 with a raft of reforms.

OPEC member Nigeria has seen its petroleum output decline in recent years due to widespread theft from pipelines, attacks and high operating costs that deter onshore investors.