Mumbai, Sep 28 (IANS): In a relief to Anil Agarwal-promoted Vedanta Group, state-run Oil and Natural Gas Corp has agreed to it buying the India assets of Britain-based Cairn Energy, a deal worth about $9 billion.

ONGC's approval comes almost two months after the government gave its nod to the transaction. Cairn has already sold a 10 percent stake in the Indian subsidiary.

"The board of ONGC resolved that Cairn's request may be agreed to, subject to Cairn, Vedanta and other affiliates executing a formal agreement with ONGC agreeing to the royalty and cess conditions," the state-owned explorer said in a statement to the exchanges.

Cairn Energy became a major player in the energy space after its huge oil find in Barmer, Rajasthan, in 2007.

The average crude oil production from Mangala oilfield situated in the Barmer block is currently over 44,300 barrels per day (bpd) and is in the process of being ramped up to the plateau rate of 125,000 barrels.

The block is estimated to hold reserves of 6.5 billion barrels of energy equivalent.