Jakarta:State-run National Aluminium Co. Ltd (NALCO) said on Tuesday it wants to buy stakes in Indonesian coal mines to secure supplies for its aluminium project in East Kalimantan at Borneo island.

The firm said in a statement that it wants to invest in coal mines that can produce coal with heating value of more than 5,000 kcal/kg, air-dried basis (ADB) and which are able to produce 10 million tonnes per annum of coal from 2014.

Nalco needs 8-10 million tonnes per year of thermal coal, of which half will be used to feed its East Kalimantan project and the remainder for its operations outside Indonesia.

Interested coal miners should submit proposals within 30 days, the firm said in a statement published in the Jakarta Post newspaper.

Nalco plans to build a 0.5 million tonnes aluminium smelter and a 1,250 megawatts coal-fired power plant, saying its investment was estimated at $4 billion.

The Investment Coordinating Board said in July that foreign direct investment was expected to increase around 25 percent this year, showing investors are increasingly willing to take longer-term bets on a country seeing strong inflows into its stocks and bonds.