SHANGHAI, Sept 8 (Reuters) - China’s blue-chip stocks fell on Wednesday as central bank officials vowed to maintain a prudent monetary policy, while state media said the country’s long-term economic policy remains unchanged. The blue-chip CSI300 index fell 0.4% to 4,972.13, while the Shanghai Composite Index was flat at 3,675.19 points. ** China’s central bank officials said liquidity supply and demand will remain balanced in the coming months, and China will maintain prudent monetary policy without resorting to flood-like stimulus. ** Based on the message, Nomura lowered the probability of a targeted reserve requirement ratio (RRR) cut in September-October to 50% from 70% previously. ** “The PBoC could opt to use some alternative low-profile and more targeted tools for supporting groups such as SMEs,” said Nomura in a note, citing small-and-medium enterprises. ** State media outlet People’s Daily said on Wednesday China’s long-term economic policy remains unchanged and regulations on its industries are to promote their healthy development. ** The consumer staples sub-index, the new energy sub-index and the machinery sub-index fell 1.2%, 2%, and 2.5%, respectively. ** The coal sub-index surged 3.3%, as the tight coking coal supply in China has fuelled the rally in prices of the steelmaking ingredients. ** China’s state planner has banned an influential coal trading firm from publishing price assessments and market news, part of government efforts to regulate commodities markets and tame hot prices. ** The infrastructure sub-index jumped 2.3% to its highest in nearly two years. (Reporting by Shanghai Newsroom; Editing by Ramakrishnan M.) Our Standards: The Thomson Reuters Trust Principles.