Beef exporters were formally told by the government that, as of Monday morning, issuance of international health certificates was suspended to comply with provisions of a bilateral health protocol signed by Brazil and China.

Listed Brazilian meatpackers including Minerva SA fell by almost 5% in late afternoon trading. JBS SA, and Marfrig Global Foods each dropped by about 3%.

The source said the bilateral protocol foresees preemptive measures in cases such as occurrence of bovine spongiform encephalopathy (BSE), as mad cow disease in known, whether or not it manifests itself in classic form.

After the atypical case was reported in Brazil last week, the agriculture ministry banned exports and communicated with China, which will now assess the situation and give feedback to Brazilian authorities, the source said.

The suspension affects all Brazilian beef exporters to China as per provisions in the bilateral protocol, the source said, adding that the fact it is an isolated case means the ban will likely be short-lived.

Newspaper Valor Econômico reported earlier on Monday that Brazil's Agriculture Ministry has preemptively suspended beef exports to China after authorities found an atypical case of mad cow disease in Mato Grosso, Brazil's leading agriculture state.

The ministry did not have an immediate comment.

On Friday, the Brazilian government reported a case of atypical mad cow disease in an animal in Mato Grosso.

(Reporting by Ana Mano; Editing by Cynthia Osterman and Tom Brown)

By Ana Mano