* SSEC +1%, CSI300 +1%, HSI +2%, HSCE 2.1%
* Stocks track global rally amid rumours of coronavirus vaccine
* Cheap valuation, policy support to help - analyst
HONG KONG, Feb 6 (Reuters) - China shares climbed for a third session on Thursday, as investors counted on cheap valuation and policy support from the central bank after markets were hammered by fears of a coronavirus outbreak.
** At the midday break, the Shanghai Composite index jumped 1% to 2,845.89 points. The blue-chip CSI300 index gained almost 1%.
** CSI300's financial sector sub-index rose 0.3%, the consumer staples sector gained 1.3% and the healthcare sub-index was up 2.9%.
** Chinese H-shares listed in Hong Kong rose 2.1%, while the Hang Seng Index climbed 2% to 27,312.45.
** The smaller Shenzhen index was up 2.1% and the start-up board ChiNext Composite index rose 2.7%.
** Shortly after the morning session, China said it will halve tariffs on some goods imported from the United States starting on Feb. 14, and reiterated that it hopes it can work with Washington to eventually scrap all tariffs in bilateral trade.
** The rise in domestic markets followed a global rally late Wednesday, which traders attributed to vague rumours of a possible vaccine or a drug breakthrough for the coronavirus, although they also said such catalysts were likely to be an excuse for short-covering.
** The World Health Organization played down such media reports on Wednesday of "breakthrough" of drug discovery.
** Share prices this week were also aided by policymakers' efforts to prevent heavy selling, including liquidity injections and de facto restrictions on selling.
** "We believe market valuations currently are relatively attractive, (we) can also expect adjustment policy (support)," analysts at Galaxy Securities wrote in a report on Thursday, though they added it will take time for stocks to recover.
** Others remain sceptical. Pictet Asset Management said on Thursday they have reduced equities "across the board" in Hong Kong and Mainland China as these are "economies that are most affected" by the coronavirus.
** Around the region, MSCI's Asia ex-Japan stock index was firmer by 1.3%, while Japan's Nikkei index was up 2.5%.
* The yuan was quoted at 6.9621 per U.S. dollar, 0.19% firmer than the previous close of 6.9753.
** The largest percentage gainers in the main Shanghai Composite index were Zhongzhu Healthcare Holding Co Ltd, up 10.17%, followed by Henan Taloph Pharmaceutical Stock Co Ltd , gaining 10.07% and Northern United Publishing & Media Group Co Ltd, up by 10.06%.
** So far this year, the Shanghai stock index lost 6.7%, while China's H-share index dropped 4%. Shanghai stocks have declined 4.4% so far this month.
** As of midday, China's A-shares were trading at a premium of 23.30% over the Hong Kong-listed H-shares.
** The Shanghai stock index is below its 50-day moving average and below its 200-day moving average.
(Reporting by Noah Sin in Hong Kong, Editing by Sherry Jacob-Phillips)