* SSEC flat, CSI300 -0.1 pct, HSI +0.2 pct
* Yuan weakens on corporate dollar buying despite stronger fixing
* State planner calls for stepped up measures to boost investment
SHANGHAI, Aug 28 (Reuters) - Chinese stocks took a breather on Tuesday morning and were flat after strong gains on Monday, as the central bank took steps to stabilise the yuan, and as news of U.S. and Mexico agreeing to overhaul a trade pact brought relief to the region.
** China’s central bank raised its daily guidance rate for the yuan by the most in nearly 15 months on Tuesday as part of its latest move to put a floor under the currency.
** China’s state planner said Monday the country’s investment growth, already at record lows, may weaken even further in the future and authorities should step up fiscal and financial measures to give it a boost.
** The U.S. Commerce Department said on Monday it had made a preliminary determination that imports of certain steel wheels from China were subsidized, and that it would impose duties.
** The United States and Mexico agreed on Monday to overhaul the North American Free Trade Agreement (NAFTA), putting pressure on Canada to agree to new terms on auto trade and dispute settlement rules to remain part of the three-nation pact.
** At the midday break, the Shanghai Composite index was almost unchanged 2,780.98.
** China’s blue-chip CSI300 index was down less than 0.1 percent, with its financial sector sub-index lower by 0.29 percent, the consumer staples sector down 0.94 percent, the real estate index up 0.19 percent and the healthcare sub-index down 0.26 percent.
** Chinese H-shares listed in Hong Kong rose 0.25 percent at 11,076.46, while the Hang Seng Index was up 0.24 percent at 28,340.20.
** The smaller Shenzhen index was unchanged for the day and the start-up board ChiNext Composite index was weaker by 0.13 percent.
** Around the region, MSCI’s Asia ex-Japan stock index was firmer by 0.46 percent while Japan’s Nikkei index was up 0.48 percent.
** The yuan was quoted at 6.818 per U.S. dollar, 0.03 percent weaker than the previous close of 6.816.
** The largest percentage gainers in the main Shanghai Composite index were Shijiazhuang Kelin Electric Co Ltd, up 10.03 percent, followed by SEC Electric Machinery Co Ltd , gaining 10.02 percent and Huada Automotive Technology Co Ltd, up by 10.01 percent.
** The largest percentage losses in the Shanghai index were Shenzhen Geoway Co Ltd, down 10.06 percent, followed by Shangying Global Co Ltd, losing 9.33 percent and Fujian Longma Environmental Sanitation Equipment Co Ltd , down by 8.19 percent.
** So far this year, the Shanghai stock index is down 15.91 percent, while China’s H-share index is down 5.6 percent. Shanghai stocks have declined 3.32 percent this month.
** The top gainers among H-shares were Shenzhou International Group Holdings Ltd, up 6.65 percent, followed by Sinopharm Group Co Ltd, gaining 5.84 percent and China Shenhua Energy Co Ltd, up by 3.28 percent. ** The three biggest H-shares percentage decliners were ZhongAn Online P & C Insurance Co Ltd, which has fallen 5.39 percent, China Gas Holdings Ltd, which has lost 2.1 percent and Anhui Conch Cement Co Ltd, down by 1.3 percent.
** About 7.29 billion shares have traded so far on the Shanghai exchange, roughly 54.3 percent of the market’s 30-day moving average of 13.43 billion shares a day. The volume traded was 13.28 billion as of the last full trading day.
** At midday, China’s A-shares were trading at a premium of 17.47 percent over Hong Kong-listed H-shares. ** The Shanghai stock index is below its 50-day moving average and below its 200-day moving average. ** The price-to-earnings ratio of the Shanghai index was 12 as of the last full trading day, while the dividend yield was 2.7 percent.
** So far this week, the market capitalisation of the Shanghai stock index has risen by 1.88 percent to 29.60 trillion yuan.
** In Hong Kong, the sub-index of the Hang Seng index tracking energy shares rose 0.5 percent while the IT sector rose 0.6 percent. The top gainer on Hang Seng was Want Want China Holdings Ltd, up 3.3 percent, while the biggest loser was Country Garden Holdings Co Ltd, which was down 3.29 percent.
Reporting by Andrew Galbraith; Editing by Gopakumar Warrier