Indika, which currently holds about 20% of Nusantara, is to pay $15 million for 25% ownership, with another $25 million to increase its stake to 40% due upon a final investment decision.
Indika's subsidiary PT Petrosea is also to provide deferred payment terms of $40 million via a front end engineering and design contract and EPC contract.
All going to plan Nusantara and Indika will seek debt funding of $110-120 million for Awak Mas' development, with the balance of about $60 million to involve equity - of which $40 million is spoken for with the deal unveiled today.
Awak Mas is slated to produce about 100,000oz at all-in sustaining costs of $760 per ounce.
Nusantara started the current quarter with about A$5 million cash.
Shares in Nusantara were up 1% to 41c in midday trade, capitalising the company at $69 million.
The stock has doubled in value over the past year.