* SSEC +1.13%, CSI300 +1.28% * Healthcare stocks jump 3.27%; Jiangsu Hengrui leads gains * Yuan weakens to 6.5346 per dollar SHANGHAI, Dec 17 (Reuters) - China’s blue-chip index ended higher for the fourth straight session on Thursday, powered by healthcare, consumer staples and financials sectors, on investor optimism over swift recovery in the world’s second-largest economy. ** At the close, the Shanghai Composite index was up 1.13% at 3,404.87. ** The blue-chip CSI300 index was up 1.28%, with its financial sector sub-index higher by 1.46%, the consumer staples sector closed 1.43% firmer and the real estate index ended 0.67% higher. ** Healthcare shares were the standout performer on the day, with the sector’s sub-index gaining 3.27%, powered by an 8.42% jump in shares of Jiangsu Hengrui Medicine Co Ltd ** HKEX data showed Hengrui was the second-most traded A-share through the Northbound leg of Stock Connect on Wednesday after the company announced promising results about a cancer drug. ** The smaller Shenzhen index ended 0.96% higher and the start-up board ChiNext Composite index was higher by 0.905%. ** Index gains mirrored strength across broader markets as investors welcomed the U.S. Federal Reserve’s pledge to keep funneling cash into financial markets until the U.S. economic recovery is secure. ** Market focus has turned to the prospect of a pre-Christmas fiscal package from U.S. Congress. ** Congressional negotiators were haggling on Wednesday over details of a $900 billion COVID-19 aid bill that is expected to include $600-$700 stimulus checks and extended unemployment benefits, as a Friday deadline looms. ** Around the region, MSCI’s Asia ex-Japan stock index was up 1.14%, while Japan’s Nikkei index closed 0.18% higher. ** At 0704 GMT, the yuan was quoted at 6.5346 per U.S. dollar, 0.04% weaker than its previous close of 6.5323. ** So far this year, the Shanghai stock index is up 11.6% and the CSI300 advanced 22.5%, while China’s H-share index listed in Hong Kong is down 5.9%. Shanghai stocks have climbed 0.39% this month. (Reporting by Andrew Galbraith, Editing by Sherry Jacob-Phillips)