SAO PAULO (Reuters) - Brazil has canceled a 10-year-old ban on sugarcane cultivation in its Amazon rainforest and central wetlands, the government gazette said on Wednesday, a move environmentalists criticized as another assault on the country’s sensitive ecosystems.

The government said the decision, signed by President Jair Bolsonaro and the ministries of economy and agriculture, was taken because the 2009 decree was obsolete and other regulatory instruments, such as the new forest law and the RenovaBio program, were more efficient for this type of oversight.

Although areas under sugarcane cultivation are being reduced in Brazil, green groups worry that the crop could eventually be planted in recently cleared areas in the Amazon, the world’s largest rainforest.

Environmentalists said the decision was another step by the Bolsonaro government to reduce protections for the Amazon, whose preservation is considered important to control emissions of greenhouse gases.

Ending the prohibition will expose the Amazon and other vulnerable areas to “predatory economic expansion,” Brazil’s Climate Observatory, a network of green groups including the World Wildlife Fund, Conservation International and others, said in a statement.

Brazil’s cane industry group Unica on Wednesday called the ban anachronistic and said that other tools, such as the new Brazilian Forest Code, were sufficient to regulate agricultural activities in environmentally vulnerable areas.

Leftist leader Luiz Inacio Lula da Silva introduced the ban at a time when the sugarcane product ethanol was being championed as an environmentally friendly biofuel that would help countries reduce their carbon footprints.

Brazil is the world’s largest producer of sugarcane.

The excitement over ethanol’s prospects led to worries that expanding cane cultivation in Brazil could lead to deforestation and occupy land that could be used for food production.

The market failed to pan out, however. Exports remain limited with Brazil and the United States being the only countries producing and using ethanol on a large scale.

Instead, the area planted with cane has been reduced over the past five years, partly due to low global sugar prices.

Former Environment Minister Carlos Minc, who was behind Lula’s decision to introduce the ban, said reversing the decree would hurt the eco-friendly image of Brazilian agriculture.

“This decision will tarnish the image of Brazilian ethanol in the world,” Minc said in a Twitter posting.