Hong Kong and Shanghai stocks slipped on Thursday morning, extending the previous day’s losses after another Wall Street sell-off as investors fret over the state of the global economy. The Hang Seng Index in Hong Kong sank 0.35 per cent, or 71.75 points, to 20,454.08 by the break. Shanghai’s benchmark composite index slipped 0.27 percent, or 8.21 points, to 2,983.06 and the Shenzhen Composite Index, which tracks stocks on China’s second exchange, edged down 0.07 percent, or 1.37 points, to 1,927.26.