TNK Brasil will now operate the concessions under a joint operating agreement (JOA), which has been approved by shareholders.

The company agreed in October to pay $1bn for a HRT’s Solimoes block stake, with an option for an additional 10%, reports Bloomberg.

HRT chief executive officer Marcio Rocha Mello said " The Solimoes Project will benefit from their experience and expertise developed in Russia and from lessons learnt from developments in Siberia with similar logistical challenges."

TNK-BP chief executive officer Mikhail Fridman said "TNK-BP’s growth strategy foresees the company’s transformation into a leading private oil and gas company, both inside and outside of Russia."

The approval also concludes the sale between HRT and TNK Brasil.

The blocks contain potential reserves of between 4 billion and 6 billion barrels of light oil and between 10 trillion and 20 trillion cubic feet of natural gas.