A Russian delegation visiting Tehran on Friday signed a handful of agreements to work with an Iranian oil company, a managing director said.

More than two dozen representatives from top major oil and gas companies in Russia, including Gazprom, are in Iran this week to discuss opportunities in the opening Iranian energy sector. Gholam-Reza Manouchehri, the deputy managing director of the National Iranian Oil Co., said memoranda of understanding were signed with three Russian oil companies.

"The documents were inked between Iran and the Lukoil, Tatneft and Zarubezhneft of Russia," he was quoted as saying by the semiofficial Fars News Agency.

The Russian agreements followed a similar arrangement between the NIOC and Norwegian oil and gas producer DNO. The Norwegian company said it would examine the possibilities for the development of the western Changuleh oil field, which is estimated to hold more than 2 billion barrels of oil in place.

The field, near the border with Iraq, was discovered in the late 1990s but never developed. DNO's deal comes roughly one week after French energy company Total confirmed the signing of a preliminary arrangement to work alongside a Chinese company in producing offshore Iranian gas.

Iran is working to bring foreign investors back to an energy sector previously shuttered by sanctions imposed for its controversial nuclear sector. Iran and Russia have established energy ties, with the latter supplying some of the fuel needed to power the Bushehr nuclear power plant in Iran.

Two years ago, when the sanctions noose was tightening on Tehran, Iran and Russia, itself under financial pressures, were reviewing the potential for an oil-for-goods deal. Iran at the time was cleared to export around 1 million barrels of oil per day and the swap had the potential to allow for an additional 500,000 bpd.

No terms of the agreements with the Russian oil companies were outlined in the Iranian media. Speaking from the sidelines of a summit in Doha, Russian Energy Minister Alexander Novak said it was incumbent on major oil producers to keep output in check.