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By Bozorgmehr Sharafedin and Oksana Kobzeva

TEHRAN/MOSCOW/BEIRUT, Dec 13 (Reuters) - Russian oil producer Gazprom Neft SIBN.MM and National Iranian Oil Company (NIOC) agreed on Tuesday to conduct a study into the possible development of two oil fields in Iran, Russia's energy ministry Alexander Novak said.

Iran, OPEC's third largest oil producer, plans to launch next year a new-style contract for helping develop its oil and gas fields with invitations to tender to be the first since the lifting of sanctions.

Novak said Gazprom Neft, the oil producing unit of gas monopoly Gazprom GAZP.MM , has signed a memorandum of understanding with NIOC and Gazprom Neft will now conduct a study for the Changouleh and Cheshmeh-Khosh oil fields in Western Iran. A deal on producing oil at the two fields could follow, the minister said.

He also said on Tuesday that Gazprom and Russia's largest oil producer Rosneft ROSN.MM have signed a separate memorandum with NIOC.

Gazprom Deputy Chief Executive Alexander Medvedev told reporters in Tehran that his company has been interested in joint liquefied natural gas (LNG) projects.

Russia, which has already signed several memorandums of understanding with Iran, has the largest share of Iran's oil field development studies compared with other countries involved in oil exploration there, Iran's oil minister Bijan Namdar Zanganeh was quoted as saying by ISNA news agency.

Zanganeh also said Iran would finalise another deal in the next two days to sell Russia 100,000 barrels of crude oil per day.

Commenting on the recent OPEC deal to cut oil output, Zangeneh said: "The talks between the two countries' leaders were essential and very significant in this matter."

He said oil prices were likely to settle at $50-55 per barrel.

"No other country may have influence on Russia's and Iran's intention to develop ties", Iranian Communications Minister Mahmoud Vaezi said at the talks with Russia's Novak.

(Reporting by Bozorgmehr Sharafedin in Beirut and Oksana Kobzeva in Tehran, additional reporting by Vladimir Soldatkin in Moscow,; writing by Denis Pinchuk; Editing by Andrey Ostroukh, Greg Mahlich) ((vladimir.soldatkin@reuters.com; +7 495 775 12 42; Reuters Messaging: vladimir.soldatkin.thomsonreuters.com@reuters.net))