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ANKARA, Oct 4 (Reuters) - The National Iranian Oil Company (NIOC) on Tuesday signed a long-awaited new model contract with an Iranian firm while the OPEC producer hopes to attract foreign energy investors to boost output after years of international sanctions.

"The first new model contract, the Iran Petroleum Contract (IPC), to develop the second phase of Yaran field also an EOR (enhanced oil recovery) and IOR (improved oil recovery) contracts for Koupal oil field were signed," the Oil Ministry's official website SHANA reported.

SHANA said that the value of the contract signed with a group of local Iranian companies is worth $2.5 billion.

After reaching a landmark nuclear deal with six major powers in 2015, sanctions imposed on Tehran were lifted in January, in exchange for Iran curbing its nuclear programme. OPEC member Iran, the No. 4 crude exporter, seeks to raise its crude output to the pre-sanction levels of 4 million bpd.

Hardline rivals of Iran's pragmatist President Hassan Rouhani have criticized the IPC, which ends a buy-back system dating back more than 20 years under which foreign firms have been banned from booking reserves or taking equity stakes in Iranian companies.

Oil majors have said they would only go back to Iran if it made major changes to the buy-back contracts, which companies such as France's Total TOTF.PA or Italy's Eni ENI.MI said made them no money or even incurred losses.



(Writing by Parisa Hafezi, editing by Louise Heavens) ((parisa.hafezi@thomsonreuters.com; +90 532 176 3452; Reuters Messaging: parisa.hafezi@thomsonreuters.com))