The Paranagua Export Corridor Terminals Association (Atexp), comprising a group of 10 companies that operate in the facility, ships approximately 20 million tons of grains per year using that structure, according to its website.

A spokesperson for the port told Reuters the inoperative conveyor belt has not disrupted grain exports via the corridor, adding that five out of a total of six belts remain operational.

"Auditors from the ministry of labor found serious maintenance issues and excessive dust accumulation, which could lead to an explosion," shipping agent Williams said on Wednesday.

Williams added that the order to stop the conveyor belt may delay ship loading.

Atexp, whose exporters include Cargill and Louis Dreyfus Company, did not immediately reply to a request for comment.

The labor ministry could not be reached for comment. The order to idle the belt took effect on April 1, the port's spokesperson said.

(Reporting by Ana Mano; Editing by Sandra Maler)

By Ana Mano