Chilean pulp and wood panel maker Arauco, the forestry arm of industrial group Empresas Copec, on Wednesday estimated it could take a $50 million hit due to fires raging in the country's south.    Some 47,000 hectares of plantations, mainly pine forests it uses to manufacture its wood products, could potentially be affected, the firm said in a letter to the local regulator.    The Andean country is battling some of the worst wildfires in years that have claimed more than 20 lives and burned through over 440,000 hectares.   ...