The Sensex at the Bombay Stock Exchange today dropped below the 17,000 level after more than three and a half week and was trading 182 points down at 16,976. The fall was attributed to sustained selling pressure from operators ahead of the expiry of derivatives contracts on Thursday amid lower Asian cues.Maruti Suzuki India tumbled 4.85 per cent. The company has issued a notice declaring lockout at the company's Manesar plant in Haryana after the violence at the factory resulting in the death of a senior official and injuring 100 others. The 30-share barometer fell by 153 points to trade at 17,005 in its opening session.