VIENNA - Iran on Wednesday named seven Western oil companies it wants back in its vast oil and gas fields once international sanctions are lifted and said it would offer contract terms in April next year.
Iranian Oil Minister Bijan Zanganeh named the seven in order: Total of France, Royal Dutch Shell, Italy's ENI, Norway's Statoil, Britain's BP and US companies Exxon Mobil and ConocoPhillips.
Iran has the world's fourth-largest proved national reserves of oil - most of it cheap to produce - and is also home to the biggest proved reserves of natural gas, some 18 percent of the global total.
But with nationalization in the Islamic revolution of 1979, the oil companies were thrown out. Iran's share of world oil production fell to below 40 percent by 1997 from 55 percent in the 1970s. Its gas output remained negligible.
Oil companies from around the world drifted back in the 1990s, and Zanganeh oversaw their return as minister under the reformist government of 1997-2005.
Total returned to onshore fields in 1997 and Shell in 1999, both while Zanganeh was minister and both in defiance of the US sanctions of the time, even though President Bill Clinton had blocked a Conoco project in 1995.
But Iran's production stagnated through the 2000s amid growing international tensions over its nuclear program. The more effective sanctions instituted in 2012 have choked out foreign investment and sent output down to 2.65 million barrels a day in November from an average of 4.3 million in 2011.
Iran last month reached an interim deal with six western powers to limit its nuclear program, under which sanctions on oil investment and trade with Iran may be lifted next year.