USX said talks were continuing with bidders on other oil and gas assets.

Some analysts have suggested that buyers are taking control of natural gas assets near the height of the market.

The acquisition continues a push by American energy companies to collect natural gas assets in Canada.

It is involved in exploration, acquisition, and management of international oil and gas assets of Gazprom.

Shell also postponed the publication of its 2003 annual report for two months to complete a review of its oil and gas assets.

Unocal has put its California oil and gas assets up for sale.

In 2008 it acquired six proven but undeveloped gas assets from Tullow Oil.

It will also own international oil and gas assets and engineering and metallurgical technologies businesses.

Analysts pointed out that the company had sold other oil and gas assets.

It has a portfolio of eight oil and gas assets across India, Thailand and Egypt.