The Sensex at the Bombay Stock Exchange gained over 100 points to cross the 17,000 level in late morning deals on buying by funds and retailers after Finance Minister Pranab Mukherjee said on Saturday that the government will announce measures today to improve market conditions. The 30-share barometer, gained over 120 points, to trade at 17,092.Similarly, the Nifty at the National Stock Exchange also gained 33 points to 5,178.