Reports suggest CNOOC is to announce that it is buying a $2bn (£1.1bn) stake in a Nigerian oil and gas field. CNOOC last year failed to buy US firm Unocal following what it called unprecedented political opposition to its plans from US lawmakers. CNOOC wants to finds oil and gas assets overseas to supply its domestic market. China's appetite for these energy resources is second only to that of the United States. CNOOC is one of four big oil companies created when the country's oil industry was restructured seven years ago. Its parent company is controlled by the Chinese government. CNOOC shares were suspended before the start of trading in Hong Kong on Monday, reportedly ahead of an announcement that it plans to buy a stake in a major Nigerian oil and gas field operated by the firm Total. Stocks are routinely suspended ahead of the release of information that could significantly affect a company's share price. The field CNOOC is expected to invest in is about 200km off the coast of Nigeria. It was first discovered six years ago and is reported to need billions of dollars of investment before it comes on stream in two years time. CNOOC has bought access to overseas oil and gas resources in a number of countries in recent years, including Indonesia and Australia. PIN/BBC