* CSI300 +0.51%, SSEC flat, HSI +0.96% * China exports grow strongly in March, import growth at 4-year high * China c.bank official vows policy continuity SHANGHAI, April 13 (Reuters) - Chinese blue-chip shares edged higher on Tuesday after new data showed the country’s exports rose in March, but persistent investor concerns that a solidifying recovery could prompt a shift to tighter policy kept gains in check. ** At the midday break, China’s blue-chip CSI300 index was up 0.51%. The Shanghai Composite index was flat at 3,412.67 points. ** The consumer staples sector rose 1.63% and the information technology sector added 1.48%, but the real estate index dipped 0.59% and financials slipped 0.44% ** China’s exports grew strongly in March on improving global demand as COVID-19 vaccinations progress, and import growth hit a four-year high, adding to signs of a solidifying recovery in the world’s second-largest economy. ** China will maintain continuity, stability and sustainability of its economic policies, Sun Guofeng, head of the monetary policy department at the People’s Bank of China, said on Monday. ** Chinese H-shares listed in Hong Kong rose 0.63% to 10,943.09, while the Hang Seng Index was up 0.96% at 28,727.53. ** Alibaba Group Holding Co Ltd shares continued to rise on Tuesday after China imposed a sweeping restructuring on affiliate Ant Group, underscoring Beijing’s determination to rein in its internet giants. ** “For Alibaba, the near-term overhang has been removed and there appears to have been a ‘meeting of the minds’ between management and the regulator which sets the stage for a more healthy relationship. Investors are responding positively to this sentiment,” said Tom Masi and Nuno Fernandes at GW&K Investment Management. ** The smaller Shenzhen index was up 0.63%, the start-up board ChiNext Composite index rose 2% and Shanghai’s tech-focused STAR50 index increased 0.83%. ** The yuan was quoted at 6.55 per U.S. dollar, 0.04% weaker than the previous close of 6.5475. (Reporting by Andrew Galbraith and Samuel Shen; Editing by Krishna Chandra Eluri)