The BSE benchmark Sensex declined by nearly 80 points in early trade today.The 30-share BSE index, which had gained over 287 points in the previous two sessions, declined by 79.69 points, or 0.47 per cent, to 16,659.32.In a similar fashion, the wide-based National Stock Exchange Nifty index shed 27points, or 0.53 per cent, to 5,021.In the Asia region, Japan's Nikkei Index slipped by 0.14 per cent in early trade today.