SHANGHAI, March 21 (Reuters) - China stocks slipped on Thursday, signalling a potential fatigue in their six-week rebound, while Hong Kong shares tracked regional markets higher after the U.S. Federal Reserve pledged to stick to its rate cut plans.

** Overnight, the Fed maintained its rates forecast between 5.25% and 5.5%, as expected, while nudging up the inflation forecasts. The median projection of policymakers for three 25-basis-point rate cuts this year remained unchanged from December.

** At the midday break, the Shanghai Composite index was down 0.2% at 3,073.37 points. ** China's blue-chip CSI300 index was down 0.17%, with the healthcare sub-index falling 0.58%. However, the financial sector sub-index rose 0.5%, while consumer staples sector logged a marginal 0.04% increase. Meanwhile, real estate outpaced the others with a 1.1% increase ** Chinese H-shares listed in Hong Kong rose 1.56% to 5,894.3, while the Hang Seng Index was up 1.75% at 16,832.49. ** The smaller Shenzhen index was down 0.35%, the start-up board ChiNext Composite index was weaker by 0.49% and Shanghai's tech-focused STAR50 index slipped 0.91%. ** Around the region, MSCI's Asia ex-Japan stock index was firmer by 1.91%, with Japan's Nikkei index rising 1.72%. ** The yuan was quoted at 7.1987 per U.S. dollar, 0.03% weaker than the previous close of 7.1967. ** The largest percentage gainers in the main Shanghai Composite index were Kunshan Guoli Electronic Technology Co Ltd , up 13.12%, followed by Chengdu JOUAV Automation Tech Co Ltd, gaining 10.57% and Beijing Haitian Ruisheng Science Technology Ltd, up 10.32%. ** The Shanghai index marked the largest percentage losses, with Shanghai Datun Energy Resources Co Ltd declining by 6.969%. It was followed by Sunshine Guojian Pharmaceutical Shanghai Co Ltd, which lost 6.906% and Nanya New Material Technology Co Ltd, down by 6.49%.

** In Hong Kong, the sub-index of the Hang Seng index tracking energy shares rose 1.5% while the IT sector rose 1.7%. Longfor Group Holdings Ltd emerged as the the top gainer on the Hang Seng, with a 5.96% jump, while the Sunny Optical Technology Group Co Ltd logged the largest decline, losing 11.4%. (Reporting by Shanghai Newsroom; Editing by Dhanya Ann Thoppil)