The World Trade Organisation (WTO) was established on January 1, 1995.  The multilateral trading system was originally set up under the General Agreement on Tariffs and Trade (GATT) in 1947.  In March 2005 the WTO had a membership of 148 countries and covered more than 97% of world trade.  The WTO Secretariat is located in Geneva, Switzerland.  Countries of all levels of development and size are members of the WTO.  The WTO's main function is to ensure that trade flows smoothly, predictably and freely.