Bombay stocks sold off Thursday, dropping 1.4% following three solid gains earlier in the week. The BSE Sensex dropped 177 points to close at 12,435 after earlier touching 12,671, yet another intraday all-time high. The top laggards on the index were Reliance, down 5.3%, Tata Steel , off 4.4% , and Grasim, down 2.9%. Gainers included Hindalco, up 1.7% and HDFC, up 1.3%. Larsen & Toubro shed 1.3% on plans to set up a shipyard to build huge vessels, including large crude carriers. Tata Power shed 2.6%. It reportedly plans to add thermal generation capacity. Reliance Industries said it may take a stake in the big Saudi Aramco petrochemical project in Saudi Arabia.