* SSEC -0.59%; CSI300 flat, HSI -0.24% * Yuan, Chinese government bonds stable after late sell-off * Yuan traders shift focus to U.S. Fed meeting * State-owned papers urge calm after rout (Updates to midday, adds quotes, detail) SHANGHAI, July 28 (Reuters) - Chinese shares fell on Wednesday but trimmed earlier losses amid volatile trade as state-run financial media called for calm following a wild rout triggered by investor concerns about tightening government regulation. The Shanghai Composite Index fell as much as 2% before finishing the morning session down 0.59%. The blue-chip CSI300 index clawed back some its losses to end the morning flat, but was still down more than 6.6% for the week. In Hong Kong, the benchmark Hang Seng Index flitted between gains and losses to fall 0.24% at midday after plunging an eight-month closing low a day earlier. The Hang Seng China Enterprises Index was up 0.38%. Andy Maynard, head of equities at China Renaissance in Hong Kong, said the market mood on Wednesday was “nervous” rather than panicked. “Is the downside over? No it’s not. Do we think there’s going to be more? Yes, there probably is. Do I think there’s some relief here? Yes.” The Hang Seng Tech index, which hit record lows a day earlier, was barely lower. Real estate firms in Hong Kong rose 1.5% even as a mainland index tracking the sector fell 0.45%. A CSI index tracking education firms listed on mainland and Hong Kong markets fell 0.52%. The wobbly trade in Chinese markets came as state-owned securities newspaper urged calm for A-share investors on Wednesday. The Securities Times wrote the market “will stabilise at any moment” after regulatory moves aimed at the education, property and technology sectors sparked heavy selling this week. Fixed income and foreign exchange markets were relatively steady on Wednesday after succumbing to Tuesday’s sell-off. The most-traded 10-year Chinese government bond futures, for September delivery, were last down 0.09%, following a 0.35% drop a day earlier. China’s yuan firmed from a more than three-month trough against the dollar hit a day earlier, as some investors expected major state banks could step in soon to support the currency. The yuan’s late slump fed into the People’s Bank of China’s weakest daily fixing in three months on Wednesday. Some traders said much attention had shifted from domestic markets to the outcome of a two-day U.S. Federal Reserve meeting due later in the session, which could affect the trajectory of the dollar and other major currencies. “Maybe the authorities want some weakness in the yuan for the time being, but an overshoot could definitely prompt some actions,” said a trader at a Chinese bank. The onshore spot yuan was last at 6.5055 per dollar and the offshore yuan strengthened to 6.5139 per dollar. China’s regulatory moves seem “to have led to a further reassessment of the extent to which the Chinese authorities are happy to make life more difficult for private business in the pursuit of other aims,” Oliver Allen, markets economist at Capital Economics said in a note. “That is obviously bad news for certain Chinese firms, but it need not have major consequences for markets elsewhere.” Reporting by Andrew Galbraith and Winni Zhou; Editing by Sam Holmes Our Standards: The Thomson Reuters Trust Principles.