* HK->Shanghai Connect daily quota used -1.9%, Shanghai->HK daily quota used 6.7% * HSI -1.8%, HSCE -1.8%, CSI300 +0.3% * FTSE China A50 +0.5% BEIJING/SHANGHAI, April 21 (Reuters) - Hong Kong shares ended lower on Wednesday, tracking global markets, on concerns over a resurgence in COVID-19 cases in some countries that has cast renewed doubt on the strength of a global economic recovery. ** At the close of trade, the Hang Seng index was down 513.81 points, or 1.76%, at 28,621.92. The Hang Seng China Enterprises index fell 1.78% to 10,888.52. ** The sub-index of the Hang Seng tracking energy shares dipped 2.6%, while the IT sector declined 2.4%, the financial sector ended 1.67% lower and the property sector was down 0.61%. ** Global markets retreated overnight as recent optimism about rising vaccination rates in the United States, Britain, and Europe is shifting to concern that a mounting coronavirus crisis in India and the reinforcement of travel curbs will act as a brake on the global economy. ** The top gainer on the Hang Seng was Hong Kong and China Gas Co Ltd, which gained 0.48%, while the biggest loser was ANTA Sports Products Ltd, which fell 7.67%. ** China’s main Shanghai Composite index closed flat at 3,472.93 points, while the blue-chip CSI300 index ended up 0.3%, with boost from banking, healthcare stocks after upbeat quarterly results. ** Around the region, MSCI’s Asia ex-Japan stock index was weaker by 1.13%, while Japan’s Nikkei index closed down 2.03%. (Reporting by Cheng Leng in Beijing, Luoyan Liu and Andrew Galbraith in Shanghai; Editing by Shailesh Kuber)