One of China's largest conglomerates, China International Trust & Investment Corp (Citic), is in advanced talks to buy Central Asia-focused oil producer Nations Energy for about US$2 billion, the South China Morning Post reported. If successful, Citic would probably grant a first right of refusal to its commodities arm, Citic Resources Holdings, to buy the holding, a source said. The subsidiary had earlier given up an opportunity to acquire the company amid concerns that the deal was too large. Nations Energy bought the Karazhanbas oil field from the Kazakhstan government in 1997. Proven reserves exceed 400 million barrels. The privately-held company also acquired exploration rights in Azerbaijan and has expanded into Indonesia.