The majority of the funding is from Mittal Investments, the Luxembourg-based investment firm headed by steel mogul Lakshmi Mittal.

Mittal is contributing £118 million in two tranches, the second of which will close by May 2009, while UK investment bank JPMorgan Cazenove is supplying the balance of £51 million. Both investors purchased shares at 250p.

Ophir will also convert a £49.8 million bond into 21.7 million new ordinary shares, at a price of 230p per share.

Following these transactions the company will have an implied capitalisation of £558 million, giving Mittal Investments a stake of approximately 21 per cent.

The second-largest shareholder in the company will be Mvelaphanda Holdings, a South African industrial and resources conglomerate founded by Ophir’s non-executive chairman Tokyo Sexwale.

Ophir MD Alan Stein says that the company now has the licences, equipment and funding to proceed with drilling in two central African countries, Equatorial Guinea and Gabon.

Stein adds: ‘At a time of increasing competition for both acreage and equipment, Ophir’s combination of technical expertise, proven track record and rig-sharing agreements provides a strong partner for the governments on whose behalf we seek to develop the natural resources of Africa.’