The Sensex at the Bombay Stock Exchange opened 18 points lower, at 18,367, on Friday morning, on continued selling by investors, ahead of the release of industrial output data for April. Later, after the release of the data, the Sensex declined more than 100 points. But it later recovered somewhat, to stand 88 points, or 0.5 percent in the negative zone, at 18,296, in afternoon deals, a short while ago. The 30-share Sensex has lost more than 110 points in the last two trading sessions.Stock markets in China, Singapore, Taiwan, South Korea, Hong Kong and Indonesia were down by between 0.2 percent and 1.8 percent, following weaker-than-expected trade data from China.