Increasing state control over the oil sector, the RCC began a program of nationalization, starting with the expropriation of British Petroleum's share of the British Petroleum-N.B. Hunt Sahir Field in December 1971. In <answer>September 1973</answer>, it was announced that all foreign oil producers active in Libya were to be nationalized. For Gaddafi, this was an important step towards socialism. It proved an economic success; while gross domestic product had been $3.8 billion in 1969, it had risen to $13.7 billion in 1974, and $24.5 billion in 1979. In turn, the Libyans' standard of life greatly improved over the first decade of Gaddafi's administration, and by 1979 the average per-capita income was at $8,170, up from $40 in 1951; this was above the average of many industrialized countries like Italy and the U.K.
In what month and year was a blanket nationalization of foreign oil production proclaimed?
September 1973