Mumbai: India's key equity indices plummeted on Thursday ahead of the F&O expiry, matching global counterparts and led by a significant drop in banks and metals sectors. The surge in India's key stock indices this year, fueled by tremendous liquidity and widespread retail involvement, has raised concerns about overvaluation, according to market experts.

Morgan Stanley downgraded India to 'equal-weight from 'overweight' citing expensive valuations and said it expects the markets to consolidate ahead of potential short-term headwinds.

In late trading on Thursday, the equity indexes have extended their intra-day losses and are hovering near the day's lows with market indexes BSE Sensex and Nifty 50 were trading roughly 2% lower.

BSE Sensex was down 1143 points at 60,000 while benchmark Nifty was trading down 356 points at 17,854 at 3.30 pm,  amid a weak trend in global markets and unabated foreign fund outflow.

Analysts believe relentless selling by FIIs is a key reason for this correction in the market.

The Nifty sectors indices were all in the red, down as much as 2.3%. The Bank Nifty fell more than 5% to settle at 40,652. The Nifty Metal Index dropped roughly 2%.

On a stock-by-stock basis, ITC has dropped more than 5% despite reporting a net profit of 3,697 crores for the September quarter, compared to 3,252.62 crores for the same period last year.

Titan is now trading at 2,379.05, down 3.29% after its September quarter results.

On the BSE, Kotak Bank, ICICI Bank, and Axis Bank have lost 3.23%, 3.29%, and 2.63%, respectively, in the private sector banking market.