State-owned Oil and Natural Gas Corporation -- India's most valuable company -- is considering making a rebid to acquire PetroKazakhstan, a Canadian oil firm in Kazakhstan.

Although Petrokazakhstan has already accepted a bid by China's CNPC, the deal has to be ratified by the firm's shareholders.

ONGC officials said on Wednesday that the extra-ordinary general meeting of the Petrokazakhstan board is slated for October 18, before which the company can make a revised offer.

China National Petroleum Corp clinched the PetroKazakhstan deal last month, with a winning bid of $4.18 billion against ONGC's offer of $3.98 billion.

ONGC had joined hands with global steel major Mittal Steel to scout for oil property abroad.

The Committee of Secretaries has already given the nod to ONGC Videsh Ltd, the overseas arm of ONGC, to make a counter bid.