CAPE TOWN, June 26 (Reuters) - Sierra Leone will wait

for the results of a recently-launched offshore 3D seismic

survey, its first in over a decade, ahead of potentially opening

its next oil and gas licensing round later this year, a senior

government official said on Thursday.

In partnership with the government's petroleum directorate,

consultancy GeoPartners started the six-week seismic survey last

month as part of efforts to de-risk exploration in Sierra

Leone's offshore basin.

"The reprocessing of that data is happening now with our

multi-client partners, TGS, and we are hoping to get something

to push to the market in October," Foday Mansaray, director

general at the Sierra Leone Petroleum Directorate said of a

potential licensing launch date.

He said the West African country, where the then Anadarko

Petroleum and Russia's Lukoil previously discovered oil but not

in commercial quantities, could potentially offer up to 60

offshore blocks in its sixth oil and gas auction round. The

previous round concluded in 2023.

However, the new blocks are unlikely to include ultra-deep

areas that are ordinarily open for direct negotiations, he said.

Sierra Leone has an estimated 30 billion barrels of oil

equivalent recoverable offshore, Mansaray said, including the

large Vega prospect identified by Anadarko previously, which has

some 3 billion barrels of oil recoverable.

Situated along the Atlantic seaboard and between regional

oil-producing countries, such as Ivory Coast to the south and

Senegal to the north, Sierra Leone is keen to boost its

credentials as an emerging exploration frontier.

Over the past 18 months, Shell, Petrobras

, Hess and Murphy Oil ( MUR ) have purchased

some of its licensed data, Mansaray said.

Using Namibia and Guyana as examples of how exploration has

boomed in those countries following years of inactivity, he said

Sierra Leone could be on the verge of a breakthrough.

"I firmly believe that Sierra Leone is on the cusp of

something big and we are going to be one of the next big and

successful stories."