The company is looking for exploration partners in the deep water SC 55, which contains the Marantao prospect that could hold a multi-trillion cubic feet gas field or a billion barrel oil field, and SC 51 which offers mid-sized targets such as Argao in moderately deep water.

Otto is also looking for a partner to help appraise the Calauit oil fields in SC 50, which while small, are considered to be potentially commercial in the current price environment.

Chief executive Alex Parks said the company had de-risked the prospects with modern seismic and technical work, and had brought a number of them to "ready-to-drill status".

He added that by farming down to retain a 25-50% interest in each service contract, Otto could participate in more wells and increase its chance of success.

"We are already receiving interest from a number of companies ranging from mid tier to the majors, who are keen to explore for oil and gas in the Philippines, which has tremendous hydrocarbon potential, but still remains relatively unexplored," Parks said.

EZ Dataroom is hosting the online data room for each permit, with Indigo Pool marketing the SC 55 deep-water block on Otto's behalf.