Cairn India will complete the process of seeking shareholder approval for London-listed Vedanta Resources? acquisition of majority stake in the energy major within a month, sources privy to the development said.

The company decided at its board meeting held in London late evening on Tuesday that it should go for a postal ballot to secure shareholder nod.

Cairn India board said agreeing to make the 20% royalty on the crude oil output from Rajasthan a recoverable cost ? a condition set by the government for clearing the $8-$9 billion deal ? will lead to a decline in revenues and profit after tax for the current quarter by Rs 1,291.6 crore. This condition was imposed after ONGC, Cairn’s 30% partner for the Rajasthan block, which demanded royalty sharing proportionate to their respective stakes in the field. Cairn reported an 869% jump in June quarter profit after tax at Rs 2,726.6 crore from a year ago, even as revenue jumped 342% in the June quarter to Rs 3,712.7 crore from a year ago.

Cairn has also sought co-operation from the government and ONGC for commissioning its Bhagyam field within the Rajasthan block. The director general of hydrocarbons (DGH), the upstream oil regulator, has asked for a third party technical evaluation of the field.

Cairn India managing director and chief executive Rahul Dhir said the company is now focussed on commencing production from Bhagyam ? that houses the second largest oil discovery in Rajasthan after Mangala ? coupled with the commissioning of Train Four at the Mangala processing terminal.

?The optimal development of this resource will only be possible with the active support of our joint venture partner, ONGC and the government of India,? said Dhir.

ONGC informed FE that it is actively endorsing the joint venture?s proposal for commencement of production from Bhagyam field with the completion of Mangala Produiction Terminal III facilities around October-November, 2011. ?It is expected that by this time, the requisite surface facilities for safe operations will be commissioned by Cairn to handle additional volume of oil from Bhagyam field,? the state-owned company said.

Cairn is also preparing for its exploration campaign in the frontier Mannar basin offshore Sri Lanka.