UPDATE 1-Truck drivers protest in Brazil may delay grain loading -industry group

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SAO PAULO, Aug 3 (Reuters) - Brazil grains exporters group Anec on Thursday said it will send an official communication to foreign buyers saying that protests by truck drivers in the country might delay grain loading operations at Brazilian ports.

Anec's director Sergio Mendes said protests against high diesel prices have impacted the flow of grains particularly in Mato Grosso, Brazil's top producing state. The demonstrations entered a third day on Thursday and have spread to other states such as Rio Grande do Sul and Paraná, local media reported.

"Some of our members have asked us to send an official announcement regarding this problem, so they could explain possible delays to clients," Mendes said.

Anec said currently there are enough stocks in exporting ports to continue loadings. Possible delays could occur if the protests continue for a long time.

Protesters have blocked the BR-163 federal road in Mato Grosso for long periods of the day since Tuesday. The road is a key route for the flow of soy and corn both to southern and northern ports.

There are reports of blockades in other places in Brazil, such as in Minas Gerais, the country's top coffee producing state.

Truck drivers are protesting an increase in the federal PIS/Cofins tax on fuels, which led to a jump of around 0.20 real per liter of diesel.

(Reporting by José Roberto Gomes; Writing by Marcelo Teixeira; Editing by Chris Reese)