A fire destroyed a major terminal belonging to Brazilian sugar giant Copersucar on Friday, burning some 180,000 tons of raw sugar, according to a company statement.

The fire swept through six of the company's warehouses in the southern port of Santos, injuring four people. It has been put under control, according to port authorities.

"The causes of the incident are not yet known and are being investigated," the company said.

Copersucar is the world's largest sugar and ethanol company, accounting for nearly a fifth of world's sugar exports. Its loss in the fire is about 10 percent of Brazil's monthly sugar exports.

The fire is the biggest in the history of the port, which shipped 12.8 million tons of sugar in the first eight months of this year.