BRASILIA (Reuters) - Brazil federal prosecutors are negotiating with health authority Anvisa and the agriculture ministry to reach a deal that could lift an injunction against the popular weed-killer glyphosate, a prosecutor on the case told Reuters on Friday.

Prosecutors have requested a meeting next week to discuss a deal just as a ban on glyphosate products already on the market is expected to go into effect on Monday, Brasilia-based prosecutor Luciana Loureira Oliveira said by telephone.

The deal would lift injunctions on new and existing products provided that Anvisa issues a decision in the first quarter of 2019 on the chemical’s safety and the ministry agrees not to appeal the health regulator’s decision, she said.

Court documents say billions of dollars of agricultural trade could rest on whether glyphosate is ultimately allowed in Brazil, the world’s largest exporter of soy.

Brazilian farmers widely apply the herbicide to the oilseed and other crops with Monsanto SA, owned by Germany’s Bayer AG, being the largest supplier of glyphosate products in the country.

Monsanto is also facing legal backlash in the United States with hundreds of cases alleging glyphosate causes cancer.

The Brazilian federal prosecutors’ office has said that new evidence, including a study conducted in 2015 by an arm of the World Health Organization, indicates glyphosate could cause cancer and the country should reevaluate the chemical’s safety.

A Brazilian judge ruled earlier this month to halt the registration of new glyphosate-based products in the country and to suspend existing registrations after 30 days, to remain in effect until Anvisa issues a ruling on its safety.

That deadline is expected to lapse on Monday, Oliveira said, just as farmer’s are set to start planting the soy crop next month.

The Solicitor General’s office is appealing the decision with the backing of the agriculture ministry, but the court has yet to rule on the appeal.

A deal, subject to court approval, would shelve the injunction and allow glyphosate products to be used until Anvisa reaches a decision, Oliveira said.

Getting the ministry’s agreement to abide by the ruling would potentially avoid a long process of multiple layers of appeals within Brazil’s complex legal system, Oliveira said.

“We want to abbreviate this whole process that could still be very long,” she said.

Anvisa said it was taking necessary legal action in the case and could not comment on the prosecutor’s remarks. The ministry of agriculture’s press office declined to comment on the proposed deal.

A representative for Bayer and Monsanto said the companies maintain their previous statement that 40 years of use in practice and reviews by authorities around the world have shown that glyphosate is safe to use.