1971 world oil market chronology

*January 12: Negotiations begin in Tehran between 6 Gulf producing countries and 22 oil companies.
*February 3: OPEC mandates "total embargo" against any company that rejects the 55 percent tax rate.
*February 14: Tehran agreement signed. Companies accept 55 percent tax rate, immediate increase in posted prices, and further successive increases.
*February 24: Algeria nationalizes 51 percent of French oil concessions.
*April 2: Libya concludes five weeks of negotiations with Western oil companies in Tripoli on behalf of itself, Saudi Arabia, Algeria and Iraq. Agreement raises posted prices of oil delivered to Mediterranean from $2.55 to $3.45 per barrel; provides for a 2.5 percent annual price increase plus inflation allowance; raises tax rate from a range of 50-58 percent to 60 percent of posted price.
*July 31: Venezuela's Hydrocarbons Reversion Law mandates gradual transfer to government ownership of all "unexploited concession areas" by 1974 and "all their residual assets" by 1983.
*August 15: U.S. Government institutes Phase I price controls. Invoking the powers granted to the president by the Economic Stabilization Act of 1970, U.S. President Richard Nixon orders 90-day nationwide freeze on all wages, prices, salaries and rents.
*September 22: OPEC directs members to negotiate price increases to offset the devaluation of the U.S. dollar.
*November:U.S. Phase II price controls begin. Plan is to allow for gradual 2-3 percent annual price increases, however, domestic petroleum prices remain at Phase I levels.
*December 5: Libya nationalizes the British Petroleum concession (which included the Sarir field in the Sirte Basin. Operations are transferred to the state-owned National Oil Corporation.