Black Rock managing director Ivan Burgess said the company had flagged its intention to exit from exploration in Australia some time ago.

"We believe this deal is in the best interests of our shareholders as it allows us to participate in any exploration success on EP-325, yet concentrate management time and financial resources on our core Colombian and North Sea acreage," Burgess said.

Under the terms of the agreement, Advent will pay Black Rock an 0.8% royalty on any sales of hydrocarbons from EP-325, and will assume responsibility for all future cash calls relating to EP-325 and any successive renewals, permits or licences.

Advent is a Perth-based company with onshore assets in the Bonaparte, Carnarvon, Perth and Cooper/Eromanga basins that is aim ing to list on the Australian Stock Exchange by April 1 next year.

The other partners in the permit are Strike Oil Limited, Victoria Petroleum NL and Bow Energy Limited 10%. Sun Resources withdrew early this year after the Cooper prospect failed to deliver hydrocarbons.

"Sun Resources decided it would not participate in the further exploration of the permit on the grounds of the small size of the remaining prospects and leads and limited upside to the development of the small Rivoli Gas field," the company said at the time.

But Strike has said it believes the Whalebone prospect could have up to 40 million barrels of recoverable oil.