Gholamreza Manouchehri, vice-president of the National Iranian Oil Company (NIOC), told a news conference that the huge South Azadegan oil field will be the main prize among the first tenders.
"The value of this project will be $10 billion with a final production level of 600,000 barrels of oil per day," he said in Tehran.
Manouchehri said the NIOC hoped that at least three international consortiums would bid for the "very important" South Azadegan project and that there would be "a real competition".
In early 2014, Iran's oil ministry cancelled a $2.5 billion contract for South Azadegan that had been signed five years earlier with CNPC, saying the Chinese firm had failed to meet its commitments.
Delegates from dozens of global energy firms -- including Total, Shell, BP, Statoil and ENI -- have rushed into Iran since international sanctions were lifted under a nuclear accord with world powers that came into force in January.
Iran is hungry for better technology and capital, despite a historical sensitivity to foreign firms exploiting its vast oil and gas reserves.
Ten international firms have already signed preliminary agreements with the Iranian government and 16 more are in talks, said Manouchehri.
They will have to partner with one of 11 shortlisted Iranian firms, but foreign companies will be the operator and majority stakeholders at major fields.
Iran has recently finalised new oil contracts following a long and contentious political process, and the government this week called on foreign firms to pre-register themselves for the tender process.
Gholamreza Manouchehri, vice-president of the National Iranian Oil Company, told a news conference that the huge South Azadegan oil field will be the main prize among the first tenders.
Iran will launch the first tenders to develop oil and gas projects "within two months", a top official said on Wednesday.
