Italian energy company Saipem said it signed an agreement to explore the option for working in the opening Iranian oil and gas sector.

Saipem, a subsidiary of Italian energy company Eni, signed a memorandum of understanding for "potential cooperation on major projects in Iran." The agreement was signed in the presence of Italian Prime Minister Matteo Renzi and Iranian President Hassan Rouhani in Rome.

"The MoU, signed with the Parsian Oil & Gas Development Company, envisages discussions aimed at Saipem's potential cooperation in revamping and upgrading the Pars Shiraz and Tabriz refineries [in Iran]," the company said in a statement.

SHANA, the news website for the Iranian Oil Ministry, said both sides were mulling a pipeline contract worth at least $4.3 billion, with Saipem controlling about 40 percent of any bilateral arrangement in the Iranian market.

The deal was signed in Rome during the Iranian president's first European trade mission since sanctions pressure started easing in mid-January when Iran was verified as meeting conditions outlined in a July multilateral nuclear agreement.

Rouhani's visit to Italy is the first for an Iranian president in at least a decade. Iranian Oil Minister Bijan Zangenah accompanied the president, after meeting in Tehran when representatives from Eni and French energy company Total.

The United States is maintaining some economic pressure on Iran in response to military activity. Last week, the Central Bank of Iran said national banks were allowed to reconnect to some European financial channels, however.

"It means that one main obstacle on the way of Iranian banks' international relationships is removed," the bank said.

Though Iran expects a swift return to the global oil market, Rouhani has pressed for an economy less dependent on fossil fuels than his predecessors. SHANA reports the agreement with Saipem was only one of a dozen or so reached with Italian companies.

From Rome, Iran's president said a new chapter in the national economy has begun.