Russia's state oil company Rosneft and Italy's Eni have signed a partnership agreement to tap oil and natural gas in the Barents Sea and Black Sea.
Russian President-elect Vladimir Putin reportedly attended the signing ceremony.
No financial details were immediately announced by either company.
However, Rosneft chief executive Eduard Khudainatov said the two companies' joint investments in the fields may eventually reach more than $100 billion.
Based on reporting by AFP and Reuters