A charge levied on an imported article to offset the unfair price advantage it holds due to a subsidy paid to producers or exporters by the government of the exporting country. Section 303 of the Tariff Act of 1930, as amended, provides for an assessment equal to the amount of the subsidy, in addition to other duties and fees normally paid on the imported article. Countervailing duties are permitted under Article 6 of the GATT.