The Bombay Stock Exchange benchmark Sensex opened higher by 57 points on Wednesday on buying in IT stocks led by Infosys. The 30-share index rose by 0.30 per cent, to 18,172 points. Similarly, the broad-based National Stock Exchange index Nifty gained nearly 14 points to trade at 5,453points. Brokers said increased buying by funds and retail investors in heavyweight stocks, particularly technology companies, influenced the trading sentiment.