Dominant mainland offshore oil and gas producer CNOOC and some of its subsidiaries have been named defendants in a suit filed by a production partner in Indonesia claiming rights to the mainland company's interests in Indonesia's Tangguh gas field.
CNOOC did not name the plaintiff in its annual report released last month or give background details to the case which will be heard in November.
A spokeswoman declined to comment further, except to clarify that the plaintiff was not one of the existing shareholders of the Tangguh field.
CNOOC's primary assets other than a 16.96 per cent stake in the field include holdings in five oil and gas fields bought in January 2002 from Repsol-YPF of Spain for US$585 million.
They include stakes in product-sharing contracts in southeast Sumatra, offshore northwest Java, West Madura, Poleng and Blora.
The northwest Java contract was operated by British oil company BP, while West Madura's investors included South Korea's Kodeco Energy and Indonesia's state oil firm Pertamina, according to CNOOC's previous filings.
Kodeco also had a stake in Poleng. Blora was operated by Coparex of France.