The Africa-based explorer said it will maintain its 2015 production guidance for West Africa at 66,000-70,000 b/d due to the conclusion of this dispute.

Tullow said in a statement that it has regained the 7.5% stake in the Onal Complex producing fields and the Ezanga block, and has been granted license extensions in the Onal Complex fields until 2034, with access to two small oil discoveries made within the Ezanga block in 2014.

"Our West African non-operated portfolio, which has Gabon at its heart, continues to perform exceptionally well, providing important and stable production for the Group," Tullow CEO Aidan Heavey said.

The dispute began in 2014 when Gabon’s petroleum ministry expropriated Tullow’s assets relating to a minority stake in the Onal field onshore license operated by French independent Maurel & Prom.

Tullow had said then that the license had not been due for renewal for over a decade, but that the authorities had used a request by Maurel & Prom to review the license terms as an excuse to effectively lock the UK company out of the field.

The dispute reduced Tullow’s reportable production in Gabon by around 10% in 2014 to 10,700 b/d, with the total also affected by underperformance at two other fields operated by Anglo-French company Perenco.

Tullow has had operations in Gabon for over 10 years but it had been unable to book production and revenues from the assets because of this dispute since the first half of 2014.

"The effective date for the new license is August 1, 2015, enabling Tullow to resume booking net production of 2,000 b/d for the final five months of the year," Barclays said in an analyst note.

Last week, Tullow Oil calmed investor concerns over the funding of its TEN project in Ghana after its credit facilities were extended, signaling a positive move as sustained low oil prices have been very challenging for a highly leveraged oil explorer such as Tullow.

Tullow said at the time that it had completed a routine six-monthly re-determination process with its lending banks and its available debt capacity remains unchanged at $3.7 billion.

Tullow has only non-operating stakes in around a dozen onshore and offshore licenses in Gabon.

Platts