The Sensex at the Bombay Stock Exchange slumped 208 points, or 1.4 per cent, to 15,283, in opening trade, today, on concerns over slowing domestic growth, and tumbling Asian bourses.Afterwards the market continued weak, with the Sensex standing 206 points, or 1.3 percent in the negative zone, at 15,286 a short while ago. The 30-share Sensex has already lost more than 500 points in the past three trading sessions.Other Asian markets in Japan, China, Hong Kong, Indonesia, Taiwan, Singapore and South Korea down by between 0.3 percent and 3.4 percent, amid concerns about the European debt crisis.