Libya granted multiple concessions to Esso, Mobil, ENI, Texas Gulf, and others, resulting in major oil discoveries by 1959.

[6] Under its articles of incorporation, NOC was legally restricted to Production sharing agreements (PSA) with international oil companies (IOCs) where the latter assumed all risks associated with exploration.

[7] As part of this program, NOC signed production-sharing agreements with Occidental Petroleum, Sincat (Italy), and formed a joint drilling company with Saipem (an Eni subsidiary).

Although the 1973 oil crisis increased global demand, BP's legal position made some countries wary of importing from Libya.

Eventually, all the foreign companies (excluding BP) agreed to partial nationalization, providing Libya with a substantial oil surplus.

Other concessions that were nationalized that year included those belonging to BP, Amoseas (Beida field), Hunt, Arco, Esso and Shell's 17 percent share in the Oasis Oil Company.

The last phase of the socialist period was characterized by an intensive effort to build industrial capacity, but falling world oil prices in the early 1980s dramatically reduced government revenues and caused a serious decline in Libya's advantage in terms of energy costs.

President Ronald Reagan imposed sanctions on 7 January 1986 under the International Emergency Economic Powers Act, prohibiting US companies from any trade or financial dealings with Libya, while freezing Libyan assets in the US.

The agreements included expenditure guarantees by the Libyan government, an important departure from earlier regulations, designed to help offset sanctions.

Libya's isolation became even more pronounced following the 1992 imposition of United Nations sanctions designed to force Gaddafi to hand over two suspects indicted for the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland.

Sanctions were expanded on 11 November 1993, to include a freeze on Libya's overseas assets, excluding revenue from oil, natural gas, or agricultural products.

Foreign operators were encouraged to produce exclusively for export, limited to national oil companies with pre-sanctions equity in Libya.

On 4 June 2004, US Assistant Secretary of Commerce William H. Lash announced that Libya had sent its first shipment of crude oil to the US since resumption of ties between the two countries.

[14] After a period when NOC was split between rival governments in eastern and western Libya, leaders in July 2016 reached an agreement to reunify the company's management.

[16] On 30 January 2005, Libya held its first round of oil and natural gas exploration leases since the US ended sanctions: 15 areas were offered for auctions.

In October 2005, a second bidding round was held under EPSA IV, with 51 companies taking part and nearly $500 million worth of new investment flowing into the country as a result.

Currently, 280×10^9 cu ft (7.9×109 m3) per year of natural gas is exported from a processing facility at Melitah, on the Libyan coast, via Greenstream to southeastern Sicily.

On 29 December 2005, ConocoPhillips and co-venturers reached an agreement with NOC to return to its oil and natural gas exploration and production operations in Libya and extend the 13-million-acre (53,000 km2) Waha concessions another 25 years.

NOC has the largest share of the Waha concession, and additional partners include Marathon Oil (16.33%) and Amerada Hess.

[22] In October 2013, Libya's oil minister Abdelbari Arusi revealed that the NOC was considering buying Marathon's stake in Waha.

The Ra's Lanuf refinery produces petrochemicals, utilizing naphtha as a feed stock to an ethylene plant with a capacity of 1.2 million tpy (tons per year).

In May 2005, Shell agreed to a final deal with NOC to develop Libyan oil and gas resources, including LNG export facilities.

Reportedly, Shell is aiming to upgrade and expand Brega and possibly build a new LNG export facility as well at a cost of $105–$450 million.

Libya will continue to control Tamoil Africa, which operates retail stations in Egypt and Burkina Faso, as well as other African nations.