Philippine conglomerate San Miguel Corp. (SMC.PH) said Friday it has completed its acquisition of a 10.1% stake in Indophil Resources NL (IRN.AU), the Australian miner that owns a 37.5% stake in the Tampakan copper-gold project in the country's south.

The share placement agreement, involving 48 million new shares at A$0.86 a unit for a total of A$41.29 million, gives San Miguel an exclusive right to conduct due diligence until Jan. 10 next year and decide whether it should initiate a tender offer to acquire additional shares in Indophil, the company said in a statement to the stock exchange.

The Tampakan project, controlled by Anglo-Swiss miner Xstrata PLC (XTA.LN), has a total resource estimate of 2.4 billion metric tons, with a grade of 0.6% copper and 0.2% grams a ton of gold.

The development cost of the project, said to become the Philippines' biggest mining project, is estimated at US$5.2 billion.

-By Rhea Sandique-Carlos, Dow Jones Newswires; 632-848-5051; rhea.sandique-carlos@dowjones.com