Energy giant PetroChina Co. Ltd. has pulled out of a $40 billion deal to buy natural gas from a project off Australia, leaving Woodside Petroleum Ltd. looking for new customers, reported AP.

Reasons for letting the preliminary agreement lapse were not given, but analysts said Tuesday it was probably because PetroChina had become dissatisfied with the cost in the two years since the deal was signed.

Woodside informed Australia's stock exchange on Monday that an early stage agreement for the Browse Basin liquefied natural gas project off Western Australia state had not been settled by a Dec. 31 deadline and had now lapsed.

Under the September 2007 agreement, PetroChina would potentially buy up to three million metric tons (3.3 million tons) of LNG per year from the project for up to 20 years.

At the time, it was one of Australia's largest export deals with an estimated worth of AU$45 billion ($40 billion).

PetroChina would probably look for other sources of gas, said Yang Wei, an oil industry analyst at Guotai Junan Securities in Shanghai.

"I think it's probably that the price is not right. It's too expensive," he said.

Woodside said an agreement for CPC Corporation Taiwan to buy up to three million metric tons of LNG per year for up to 20 years from the Browse project was still in place, and the company was looking for more customers.