The Sensex at the Bombay Stock Exchange opened 39 points or 0.2 per cent lower at 18,272 this morning on selling by funds and retail investors, triggered by weak global markets. Further extending its losses, the Sensex stood 69 points, or 0.4 per cent in the red, at 18.242 a short while ago.Stock markets in Japan, China, Hong Kong, Singapore, Taiwan, Indonesia and South Korea were down by between 0.3 per cent and 2.5 per cent today on continued worries about the global economic recovery. Over in the US, the Dow Jones Industrial Average had slipped 1.3 per cent overnight on disappointing economic data.