Italy’s Eni will undertake a study of Iran’s second largest gas field becoming the second major after Total to re-enter the Islamic Republic post-sanctions.

The oil and gas firm signed a memorandum of understanding with the National Iranian Oil Company (NIOC) to carry out studies on the offshore Kish field as well as on the onshore Darquain oil field, which lies in in the western Ahvaz region.

Eni had been awarded the onshore concession in 2000 in a contract worth around $600m. It ceased its Iranian operations in 2010 as sanctions forced oil majors to pull out of the Islamic Republic.

The Italian firm subsequently handed over the operation of Darquain to local partners as nuclear-related sanctions began to take effect on Iran.

Following the Joint Comprehensive Plan of Action signed in January 2016, which allowed for sanctions relief and trade with the rest of the world, Iran has invited international oil companies to develop its oil and gas assets.

Earlier this year, the NIOC pre-qualified 29 foreign companies to participate in oil and gas tenders in Iran.

Its first planned tender of Azadegan – its largest onshore oil field – which neighbours Iraq has been delayed by many months.

France’s Total, which was the first oil major to return to Iran last year signed a $4.8bn agreement with CNPC to develop phase 11 of the massive South Pars gas field.

Total’s chief executive Patrick Pouyanne said the company would go ahead with an investment of $1bn on the gas field this year.