The move could bolster conservation for Brazil's Cerrado, the world's most biodiverse savanna, at least half of which has already been destroyed for agriculture. Farming, forestry and land use account for more than a fifth of planet warming-emissions.

The firms, including Archer Daniels Midland, Bunge, Cargill and Louis Dreyfus Company, agreed that by the end of the decade they will longer buy soy from farms that destroyed any non-forest natural vegetation in the Amazon rainforest, Chaco dry woodlands or the Cerrado, said Petra Tanos of the Tropical Forest Alliance.

The commitment adds to the sector's pledge last year to eliminate deforestation by 2025.

Tanos said the move is most consequential for the Cerrado, Brazil's most rapidly expanding agricultural frontier that includes large stretches of grassland. In 2023, Cerrado destruction hit its highest point in eight years.

The Tropical Forest Alliance is a World Economic Forum initiative that works with commodities firms on environmental commitments.

Beyond the United States, the largest soy exporting nations are in South America, where natural vegetation is typically cleared to make way for farms.

In the lead up to United Nations COP28 climate change summit in Dubai, some of the companies announced even more aggressive commitments. Last month, Cargill announced it would eliminate deforestation and land conversion from its supply chains by 2025 in Brazil, Argentina and Uruguay.

Archer Daniels Midland committed to eliminating land conversion among its direct suppliers by 2025 and indirect suppliers by 2027 across sensitive South American biomes.

But the industry has a history of failing to meet past commitments. In 2010, hundreds of consumer brands pledged to reach "net zero" deforestation by 2020, but failed to meet the goal.

(Reporting by Jake Spring; Editing by Rich Valdmanis and Clelia Oziel)

By Jake Spring