(REUTERS) -- Australia-listed Indophil Resources, which holds a 37.5 percent stake in Southeast Asia's largest undeveloped copper-gold prospect, said on Monday it was considering also listing its shares in the Philippines, where a key shareholder is based.

Indophil said it was moving to strengthen its offshore alliance via a $99.4 million placement with Alsons Power Holdings Corp, which is controlled by Philippine-based Indophil shareholder, the Alsons Group.

Indophil stock rose nearly 10 percent to A$0.46 against a modest 1.3 percent gain by the wider Australian market.

Indophil is considering seeking an additional listing on the Philippine stock exchange in 2012, Indophil said.

Indophil is the smaller shareholder in the Tampakan deposit in the southern Philippines. Switzerland-based Xtrata owns 62.5 percent and is project manager of Tampakan.

Indophil estimates it will cost $5.9 billion to develop the deposit, with production starting in 2016.

At present Tampakan is believed to contain 13.9 million tonnes of copper and 16.2 million ounces of gold, it said, adding a revised mineral resource is expected to be issued by Xstrata in coming days.

The lode is projected to produce 375,000 tonnes of copper and 360,000 ounces of gold per year over 17 years, with potential to extend the operating life of the mine.

Following the placement, Alsons Group will control 19.99 of Indophil, according to Indophil.