The BSE benchmark Sensex plunged to a three-week low, closing 310 points down on heavy selling by funds, triggered by poor industrial growth data and lower- than-expected quarterly earnings outlook by IT bellwether Infosys.

A weakening global trend further dampened the sentiment.

The Bombay Stock Exchange index Sensex, which had lost 356 points in the previous two sessions, fell by 309.77 points to 18,411.62, a level last seen on June 27, as blue-chips led by Infosys Technologies suffered heavy losses.

Poor performance by IT, Tech, realty, Capital Goods and Auto sector stocks pulled down the market on emergence of data that showed the industrial growth slowed down to 5.6 per cent in May from 8.5 per cent in the same month last year.

Weak Asia and lower opening in Europe on fears the Euro zone debt crisis spreading to other regions, also impacted the Indian stocks, exposed to global markets such as software industry.

Infosys that tripped 4.27 per cent on below-expectations quarterly data and sale forecast, further pushed the market into red. The IT index suffered the most, plunging 2.74 per cent to 5,925.11, with other industry heavyweights like Wipro and Tata Consultancy falling by 1.36 per cent and 0.78 per cent respectively.

Broad-based National Stock Exchange index Nifty fell 89.95 points to 5,526.15, after dipping below 5,500 level to 5,496.95 during the session.