Eni said it would work with Rosneft under the terms of a strategic cooperation agreement reached in April.
Eni said it started a seismic survey covering two license areas in the ice-free parts of Russian waters.
Warmer temperature averages throughout the year have left parts of arctic waters like the Barents Sea free of ice for longer periods. This has exposed untapped natural resources though advocacy groups have expressed concern about possible damage to the pristine arctic environment.
Eni and Rosneft said in a joint statement Monday the survey was being conducted in compliance with Russian environmental laws.
Neither company offered an estimate of the reserve area. The Norwegian government in February said its part of the Barents Sea holds around 7.9 billion barrels of oil equivalent.