* SSEC 0.2 pct, CSI300 0.1 pct, HSI -0.4 pct
* China to step up support for economy in 2019 amid trade war
* FTSE China A50 down 0.3 pct, BNY Mellon ADR China Select Index 1.0 pct lower
SHANGHAI, Dec 24 (Reuters) - China stocks started the week on a firm note on Monday, as Beijing vowed to step up support for economy in 2019 amid trade war.
** China will ratchet up support for the economy in 2019 by cutting taxes and keeping liquidity ample, the official Xinhua news agency said following an annual meeting of top leaders amid a trade dispute with the United States.
** The CSI300 index rose 0.1 percent to 3,031.61 points at the end of the morning session, while the Shanghai Composite Index gained 0.2 percent to 2,520.58 points.
** “For the short term, the signals from the Central Economic Work Conference could have a certain soothing effect on the curbed sentiment in the market,” investment bank China International Capital Corporation Limited wrote in note.
** The ultimate effects would depend on the implementation of those policies and reforms mentioned in the work conference, the bank added.
** Sector performance was mixed, with extended losses in real estate firms offset by gains in healthcare shares, as investors hunted for bargains after a slump in healthcare firms.
** In Hong Kong, stocks retreated led by information technology firms, with Meituan Dianping and smartphone maker Xiaomi Inc down 5.7 percent and 3.8 percent, respectively.
** The Hang Seng index dropped 0.4 percent to 25,651.38 points, while the Hong Kong China Enterprises Index lost 0.4 percent to 10,062.94.
** Around the region, MSCI’s Asia ex-Japan stock index was weaker by 0.29 percent, while Japan’s Nikkei index was down 1.11 percent.
** The yuan was quoted at 6.8986 per U.S. dollar, 0.12 percent firmer than the previous close of 6.907.
** The largest percentage gainers in the main Shanghai Composite index were shares of GuangDong Super Telecom Co Ltd , up 10.02 percent, followed by Wuhan Bester Group Telecom Co Ltd, gaining 10.01 percent and Suzhou Secote Precision Electronic Co Ltd, up by 10.01 percent.
** The largest percentage losses in the Shanghai index were Guangdong Songfa Ceramics Co Ltd, down 7.44 percent, followed by China Securities Co Ltd, losing 7.34 percent and Tianjin Songjiang Co Ltd, down by 7.27 percent.
** So far this year, the Shanghai stock index is down 23.92 percent, while China’s H-share index is down 13.7 percent. Shanghai stocks have declined 2.78 percent this month.
** The top gainers among H-shares were China Tower Corp Ltd , up 2.72 percent, followed by Agricultural Bank of China Ltd, gaining 1.79 percent and Hengan International Group Company Ltd, up by 1.52 percent.
** The three biggest H-shares percentage decliners were China Vanke Co Ltd, which has fallen 2.81 percent, New China Life Insurance Co Ltd, which has lost 2.4 percent and SINOPHARM GROUP CO LTD, down by 2.3 percent.
** As of 04:00 GMT, China’s A-shares were trading at a premium of 18.27 percent over the Hong Kong-listed H-shares.
Reporting by Luoyan Liu and John Ruwitch; Editing by Rashmi Aich