Iran, Russia's Tatneft sign $1B tentative oil deal

Russia's Tatneft and Iran have signed a $1 billion preliminary deal to develop the Zagheh oil field, state TV reported Sunday, deepening Moscow's business links with Iran despite US calls for further sanctions over Iran's nuclear program.

The Zagheh oil field, located outside the town of Deilam in south Iran on the shores of the Persian Gulf, contains an estimated 3 billion barrels of heavy crude oil. (AP)