BEIJING (AFX-ASIA) – China’s National Audit Office said it has started to review the accounts and assets of nine state firms, including parent companies of China Petroleum & Chemical Corp (Sinopec) (HK 0386; SHA 600028; NYSE SNP), CNOOC Ltd (883 HK, CEO NYSE) and China Unicom Ltd (HK 0762; NYSE CHU). Six other companies included…