The Bombay Stock Exchange benchmark Sensex on Friday gained 55 points in early trade on fresh buying by funds ahead of the quarterly results of firms led by software major Tata Consultancy Services. The 30-share index rose by 55 points to 17,640 in the first five minutes of trade, continuing with its gains for the third straight day. The wide-based National Stock Exchange index Nifty rose by 20 points at 5,280 points at the same time. The Dow Jones Industrial Average had gained 0.1 per cent to 10,691 and the Nasdaq Composite was also up 0.1 per cent higher at 2,311.