PetroChina Co. (PTR) has acquired coal seam gas acreage from Molopo Energy Ltd. (MPO.AU) that it hopes could support construction of its second gas-export venture in Australia's Queensland state.

Molopo said Wednesday that China's biggest oil company has bought the properties in Queensland's Bowen Basin for 43.4 million Australian dollars ($45.5 million). The purchase price is below the carrying value of the assets and Molopo will book a A$24 million impairment charge. The small Australian company said it wants to focus on its unconventional assets in North America.

Although the deal is tiny compared to recent moves by Chinese companies on international energy assets, it shows the world's second-biggest economy is prepared to hedge its bets by investing in riskier ventures that can offer it more hands-on experience developing unconventional resources for export.

A Hong Kong-based spokeswoman for PetroChina wasn't immediately available for comment Wednesday.

Coal seam gas, also known as coal bed methane, is trapped in coal deposits hundreds of meters underground. It has never been extracted and then chilled into liquefied natural gas, or LNG, for export on a large scale and four joint ventures in Australia are attempting to be the first.

One of them is a partnership between PetroChina and Royal Dutch Shell PLC (RDSB) that hopes to produce up to 16 million metric tons of the fuel each year from a giant processing terminal on the coast. That project, however, is lagging the pack and there's concerns it could be further delayed amid rising cost and regulatory pressures.

China is also involved in a fifth, smaller venture operated by Liquefied Natural Gas Ltd. (LNG.AU), or LNG Ltd. The Australian company last year sold 19.9% of its shares to the engineering unit of China National Petroleum Corp., the state-backed parent of PetroChina.

In a statement Wednesday, LNG Ltd. said PetroChina has agreed to send the gas acquired through the Molopo deal to its project, slated to produce 3 million tons of LNG a year.

The Chinese company's engineering unit has previously agreed to provide engineering, procurement and construction services for LNG Ltd.'s project, which is also in gas-supply discussions with Australia's Westside Corp (WCL.AU).

The agreement between PetroChina and LNG Ltd. represents a significant milestone to enable its project to make a final investment decision, said LNG Ltd. Chief Executive Maurice Brand, without giving a timeframe.