Tullow Oil’s shares slumped by about 15% in London this morning following the firm’s announcement about a share placing.
Tullow said it would look to raise £607million through the sale of more than 450million new shares.
Tullow said the rights issue was subject to shareholder approval and would be fully underwritten by Barclays Bank.
The firm expects the admission to go ahead on April 6.
Its shares were down 14.83% on the London Stock Exchange to £2.02 as of 11am.
Tullow’s shares are also listed on the Irish and Ghanaian Stock Exchanges.
Since crude prices collapsed in 2014, Tullow has almost halved its headcount and is on course to generate savings of about £485million by mid-2018.
It has also shifted its exploration strategy and sold non-core assets in Mauritania and Namibia.
Its net debt at the end of 2016 was almost £4billion.