Brazilian grain exporters association Anec revised upward its forecast on Thursday for corn exports this year, but commodities traders operating in the country may still see their worse performance in a decade as margins are squeezed amid a bumper harvest. Sergio Mendes, director general at Anec, said during an industry event in São Paulo that the association sees Brazil exporting 33 million tonnes of corn this year due to a drought in Eastern Europe. That estimate rose from a forecast of 30 million tonnes released earlier in November.