"The London Gold Pool was the pooling of gold reserves by a group of eight central banks in the United States and seven European countries that agreed on 1 November 1961 to cooperate in maintaining the Bretton Woods System of fixed-rate convertible currencies and defending a gold price of US$35 per troy ounce by interventions in the London gold market.The central banks coordinated concerted methods of gold sales to balance spikes in the market price of gold as determined by the London morning gold fixing while buying gold on price weaknesses. The United States provided 50% of the required gold supply for sale. The price controls were successful for six years until the system became no longer workable. The pegged price of gold was too low and runs on gold, the British pound, and the US dollar occurred and France decided to withdraw from the pool. The London Gold Pool collapsed in March 1968.The London Gold Pool controls were followed with an effort to suppress the gold price with a two-tier system of official exchange and open market transactions, but this gold window collapsed in 1971 with the Nixon Shock, and resulted in the onset of the gold bull market which saw the price of gold appreciate rapidly to US$850 in 1980."Wikipedia, The London Gold Pool
"As a reaction to the temporary closure of the London gold market in March 1968 and the resulting instability of the gold markets and the financial systems in general, Swiss banks acted immediately to minimize effects on the Swiss banking system and its currency by establishing a gold trading organization, the Zürich Gold Pool, which helped in establishing Zürich as a major trading location for gold."