The Sensex at the Bombay Stock Exchange fell 90 points, or 0.5 per cent, to 17,550, in early trade, today, as investors sold stocks amid worries about an impending hike in key policy rates by the Reserve Bank.Remaining subdued, the Sensex, stood 80 points, or 0.5 per cent in the red, at 17,560, a short while ago. Stock markets in Japan, China, Hong Kong, Indonesia, Japan, Singapore, South Korea and Taiwan were down between 0.5 per cent and 1.5 per cent. Stocks fell amid renewed concerns about the strength of the US economic recovery.