A chronology of key events:
1947 October - 23 countries sign the General Agreement on Tariffs and Trade (Gatt) in Geneva, Switzerland, to try to give an early boost to trade liberalisation.
1947 November - Delegates from 56 countries meet in Havana, Cuba, to start negotiating the charter of a proposed International Trade Organisation.
Gatt proposals on agriculture inflamed European farmers' anger
1948 1 January - Gatt agreement comes into force.
1948 March - Charter of International Trade Organisation signed but US Congress rejects it, leaving Gatt as the only international instrument governing world trade.
1949 - Second Gatt round of trade talks held at Annecy, France, where countries exchanged some 5,000 tariff concessions.
1950 - Third Gatt round held in Torquay, England, where countries exchanged some 8,700 tariff concessions, cutting the 1948 tariff levels by 25%.
1955-56 - The next trade round completed in May 1956, resulting in $2.5bn in tariff reductions.
1960-62 - Fifth Gatt round named in honour of US Under Secretary of State Douglas Dillon who proposed the negotiations. It yielded tariff concessions worth $4.9bn of world trade and involved negotiations related to the creation of the European Economic Community.
1964-67 - The Kennedy Round, named in honour of the late US president, achieves tariff cuts worth $40bn of world trade.
1973-79 - The seventh round, launched in Tokyo, Japan, sees Gatt reach agreement to start reducing not only tariffs but trade barriers as well, such as subsidies and import licensing. Tariff reductions worth more than $300bn dollars achieved.
Anti-WTO protest in London: opponents say the organisation is an enemy of the poor
- Gatt trade ministers launch the Uruguay Round in Punta Del Este, Uruguay, embarking on the most ambitious and far-reaching trade round so far. The round extended the range of trade negotiations, leading to major reductions in agricultural subsidies, an agreement to allow full access for textiles and clothing from developing countries, and an extension of intellectual property rights.
1994 - Trade ministers meet for the final time under GATT auspices at Marrakesh, Morocco to establish the World Trade Organization (WTO) and complete the Uruguay Round.
1995 - The World Trade Organization is created in Geneva.
1999 - At least 30,000 protesters disrupt WTO summit in Seattle, US; New Zealander Mike Moore becomes WTO director-general.
2001 November - WTO members meeting in Doha, Qatar, agree on the Doha Development Agenda, the nineth trade round which is intended to open negotiations on opening markets to agricultural, manufactured goods, and services.
WTO headquarters in Geneva
2001 December - China formally joins the WTO. Taiwan is admitted weeks later.
2002 August - WTO rules in favour of the EU in its row with Washington over tax breaks for US exporters. The EU gets the go-ahead to impose $4bn in sanctions against the US, the highest damages ever awarded by the WTO.
2002 September - Former Thai deputy prime minister Supachai Panitchpakdi begins a three-year term as director-general. He is the first WTO head to come from a developing nation.
2003 September - WTO announces deal aimed at giving developing countries access to cheap medicines, hailing it as historic. Aid agencies express disappointment at the deal.
2003 September - World trade talks in Cancun, Mexico collapse after four days of wrangling over farm subsidies, access to markets. Rich countries abandon plans to include so-called "Singapore issues" of investment, competition policy and public procurement in trade talks.
Many cotton producing nations have lobbied the WTO to eliminate subsidies
2003 December - WTO rules that duties imposed by the US on imported steel are illegal. US President Bush repeals the tariffs to avoid a trade war with the EU.
2004 April - WTO rules that US subsidies to its cotton farmers are unfair.
2004 August - Geneva talks achieve framework agreement on opening up global trade. US and EU will reduce agricultural subsidies, while developing nations will cut tariffs on manufactured goods.
2005 March - Upholding a complaint from Brazil, WTO rules that US subsidies to its cotton farmers are illegal.
2005 May - WTO agrees to start membership talks with Iran.
2005 September - Frenchman Pascal Lamy takes over as WTO director-general. He was formerly the EU's trade commissioner.
2005 October - US offers to make big cuts in agricultural subsidies if other countries, notably in the EU, do the same. EU responds, but France opposes more concessions.
2005 November - WTO approves membership for Saudi Arabia.
2005 December - World trade talks in Hong Kong begin amid widespread belief that they will not succeed in making a breakthrough.
2007 December - WTO clears way for Cape Verde's membership by approving a package of agreements which spell out the terms of it's accession. Cape Verde is expected to ratify the deal by June 2008.
2008 July - Ministerial talks aimed at resuscitating the Doha Round of talks break down on ninth day of meeting after the US and India fail to find a compromise on measures intended to help poor countries protect their farmers against import surges.
2008 November - G20 leaders meeting in Washington agree to "strive" for a major breakthrough in Doha talks by the end of the year.
2008 December - Pascal Lamy drops plans to hold a ministerial meeting to seek breakthrough on Doha citing the "unacceptably high" risk of failure.
2009 March - WTO says global trade flows are set to shrink by 9% during 2009. Hardest hit will be developed nations, where trade is set to fall 10%. Poorer countries will see exports fall by 2-3%.
2010 March - Pascal Lamy predicts that the worst of global trade recession is over and WTO economists foresee 2010 world economic growth of 9.5%.
2010 June - The WTO rules that the European Union paid illegal subsidies to aircraft giant Airbus after the US lodged a complaint in a long-running dispute between the EU and US.
2010 September - Leaks of WTO report say it will order more than $20bn of cuts in US government subsidies to the Boeing aircraft manufacturer.
2010 November - G20 meeting of major economic powers in Seoul sees 2011 "window of opportunity" for the conclusion of the WTO Doha Round.
2010 December - The European Union expresses support for Russia's bid to join the WTO after Moscow agreed to cut timber export tariffs and rail freight fees. Russia is the only major economy outside the WTO.
China says it plans to appeal against a WTO ruling that the US was entitled to impose extra duties on Chinese tyre imports.
2011 January - Former WTO director-general Peter Sutherland joins British Prime Minister David Cameron and German Chancellor Angela Merkel in demanding the conclusion of the Doha talks by the end of 2011.
2011 May - Both the US and Europe Union claim victory after the WTO partly overturned an earlier ruling that Airbus received billions of euros in illegal subsidies.
2011 July - WTO upholds complaints by the US, European Union and Mexico that China had broken global free trade rules by imposing quotas and taxes on exports of certain key materials, including minerals like bauxite, magnesium and zinc. China complains.
2011 August - WTO rules that a tax levied in the Philippines on imports of alcohol breaks global rules on free trade on the grounds that it grants domestic producers who use local cane and palm sugar an unfair advantage. The US has previously urged the Philippines to open its market to foreign alcoholic drinks.
2011 December - Russia finally joins the WTO after 18 years negotiating its membership. Switzerland brokered a deal to persuade Georgia to lift its veto, which it had imposed after the 2008 Russo-Georgian war.
WTO agrees terms for Samoa and Montenegro to join in 2012.
2012 January - The WTO rejects China's appeal against a ruling that it broke free trade rules by imposing quotas and taxes on exports of key materials.