Russian oil and gas company Rosneft has bought a stake in the Gulf of Mexico, taking a third (30%) of ExxonMobil’s 20 deepwater exploration blocks.

Under the agreement, ExxonMobil will keep a 70% stake in each block and remain the main operator and Rosneft’s subsidiary Neftegaz America Shelf will own the rest.

Igor I. Sechin, President of Rosneft said: “This agreement provides Rosneft and its affiliates with access to one of the world’s most prolific basins… Moreover, experience and knowledge acquired in the process may potentially be used when developing deepwater blocks in Russia, including in the Tuapse Trough in the Black Sea.”

The deal follows an earlier agreement signed by the two firms in 2011 which covered plans for exploring and developing hydrocarbon resources as well as sharing technology and expertise.