ConocoPhillips is to sell its 8.4 per cent stake in Kazakhstan oil field Kashagan for about $5 billion to Oil and Natural Gas Corp, a state-run Indian group looking to boost production.

Kashagan, the world’s biggest oilfield discovery since 1968, holds an estimated 30 billion barrels of oil-in-place, of which eight to 12 billion are potentially recoverable, with first production expected next year.

Start-up of the field has been delayed since 2005 due to cost overruns and disputes with authorities over taxes.

ConocoPhillips, which has been shedding overseas assets to cut debt and increase its investment in lower-cost domestic shale oil and gas, said the book value of assets related to its Kashagan interest was about $5.5 billion as of September 30th, and it would take an after-tax impairment of about $400 million. – (Reuters)