Dart sells China CSG assets to China Oil HBP for about $22.8m DART Energy has sold its Chinese coal-seam-gas prospects to a unit of China Oil HBP Science and Technology for about $US20.8 million ($22.8 million). The sale of a 50 per cent stake in Fortune Liulin Gas is conditional on Chinese government approval, which Dart said today it expected to obtain within two or three months.