Multilateral international treaty first created in 1947 and frequently amended (most recently in 1994, called the "Uruguay Round") to which 151 countries now subscribe.
GATT provides for fair trade rules and the gradual reduction of tariffs, duties and other trade barriers, for goods, services and intellectual property.
The 1994 amendment created a World Trade Organization (WTO), which oversees the implementation of the GATT.
References and further research:
► WTO at wto.org
► The General Agreement on Tariffs and Trade (GATT 1947) at wto.org/english/docs_e/legal_e/gatt47_01_e.htm
► Final Act embodying the results of the Uruguay Round of Multilateral Trade Negotiations at wto.org/english/docs_e/legal_e/03-fa_e.htm
► Marrakesh Agreement Establishing the World Trade Organization at wto.org/english/docs_e/legal_e/04-wto_e.htm