The Bombay Stock Exchange benchmark Sensex and National Stock Exchange's index Nifty slumped further on aggressive selling in midsession today, losing nearly 517.99 points.


The 30-share index, Sensex, fell nearly 446 points in early trade.


Markets remained bearish with a rise of over 2,370 points in the five straight sessions attracted profit selling and the index moved into negative territory since yesterday.


The selling pressure was further fuelled on reports of a weak trend in global stock markets led by the US Dow Jones Industrial Average and Nasdaq falling on reports that the US Housing sale has declined most in last decade.


The stocks of financial companies and banks were biggest losers as a fall in housing sale might cost the companies involved in lending business.


The ripples of a bearish trend were felt in domestic markets here as bankex index fell the most by 440.89 points to 6,722.59.


ICICI Bank and HDFC Bank, the country's two largest private lenders, fell the most in almost two weeks.


At midsession, the oil and gas index remained the second biggest losers by falling 511.86 points to 9,501.54.


Reliance Industries, operator of the world's third-largest refinery, dropped the most in more than a month on concerns that increasing competition in its core refining business may curb profit growth.