Essar Oil Ltd's plan to delist its shares was approved by the National Stock Exchange late last week, a company spokesman said on Monday, sending Essar shares up as much as 19.8 per cent.

Essar Oil, part of the Essar Group, now requires approval from the BSE to go ahead with the delisting process, first approved by its board in June last year.

Spokespersons for the BSE and the NSE could not be immediately reached for comment.

Essar has been in talks with Russian oil giant Rosneft over a deal to sell a key stake in its Vadinar refinery in western India but discussions have slowed over clashes on the plant's valuation.