(Recasts, adds comment from Tullow, context throughout)
DAKAR/ACCRA, Sept 23 (Reuters) - The International Tribunal for the Law of the Sea on Saturday drew an ocean boundary favouring Ghana in a dispute with its neighbour Ivory Coast, opening the way for development drilling to resume on Ghana's multi-billion dollar TEN deepwater oil and gas project.
The decade-old row between the two West African neighbours has slowed the development of oil fields and at times soured relations between the two oil producers, who also together grow 60 percent of the world's cocoa.
"The Special Chamber unanimously finds that Ghana did not violate the sovereign rights of Côte d'Ivoire," said Judge Boualem Bouguetaia, President of the Special Chamber.
An official at the court said that the boundary delineated by the tribunal did not correspond with the claim of either party. However, the angle appeared to be very close to the line claimed by Ghana.
Ivorian officials were not immediately available to comment.
"...We can now restart work on the additional drilling planned as part of the TEN fields' plan of development and take the fields towards their full potential," said Paul McDade, chief executive of London-listed oil company Tullow Oil, the lead operator of the project.
Tullow said in a statement it now expected to resume drilling around the end of the year, which would allow production to start to increase towards the full capacity of the floating production, storage and offloading vessel of 80,000 barrels per day (bpd) from around 50,000 bpd currently.
Kosmos Energy, Anadarko Petroleum Corporation , Ghana National Petroleum Corporation and PetroSA also have stakes in the TEN project.
The ruling, while expected since Ghana's claim was based on the customary equidistant line, comes as a huge relief for Ghana which is counting on oil revenues to boost its economic growth back to the levels hit before a 2014 fiscal crisis.
Ivory Coast had been seeking compensation for oil field developments in the area but the tribunal rejected this claim.
Analysts had predicted that a loss for Ghana would have resulted in complicated contract renegotiations and loss of significant revenue that could worsen the economy, dogged by high public debt. Tullow has said it has already invested around $4 billion in the TEN project.
Ghana, also Africa's second largest gold producer, discovered oil in 2007, prompting its western neighbour to revive a claim to some of its territorial waters. Several rounds of talks failed to result in a deal on the border which, like many other African sea borders, had until now never officially been set. (Additional reporting by Loucoumane Coulibaly; editing by Mark Heinrich, Greg Mahlich)