Iran is ready to launch its new contract model by the end of November to attract foreign investment in its oil and gas sector, according to the country’s oil minister.

The Iranian Petroleum Ministry has drawn up new deals to replace the buy-back model that was introduced in the 1990s, but has largely failed to attract widespread investment in the sector.

“The new oil contracts and the projects to be developed within their scope will be introduced to foreign investors in a conference in Tehran in the month of Aban (23 October-21 November),” Bijan Zangeneh, the country’s Petroleum Minister, told the ministry’s Shana news service.

Elham Aminizadeh, Iran’s vice-president for legal affairs, said the new oil deals were verified by the cabinet last week and will be “attractive to investors while securing the country’s interests and maintaining its sovereignty over the oil reservoirs”, according to Shana.

Iran is likely to begin awarding contracts under the new structure after nuclear-related sanctions are lifted against the country in line with the international deal signed in Vienna in July.

Tehran has said it plans to award $100bn of energy deals after sanctions are lifted against its banking and oil and gas sectors.

The government initially planned to announce the new contracts at a conference in London in December, but this event has now been postponed until February 2016.

The terms of the new Iranian Petroleum Contract (IPC) have not been publicly released, but it is estimated that international oil companies (IOCs) will be offered the opportunity to invest in between 34 and 74 oil fields throughout Iran. The terms of the IPCs have been described as a joint venture with the IOC and a subsidiary of National Iranian Oil Company (NIOC).

According to reports, IOCs are expected to be able to book reserves on their balance sheets. The firms will be able to participate in the oil production phase of the project and will be offered much longer-term contracts than under the buy-back model, where IOCs only participate in the development phase.