Mumbai: A benchmark index for Indian equities closed in the negative terrain for the fourth straight day on Wednesday as the State Bank of India's ratings downgrade dampened sentiments on Dalal Street. The 30-scrip sensitive index (Sensex) of the Bombay Stock Exchange (BSE) opened in the positive at 15,967.72 points and closed at 15,792.41 points, down 0.46 percent or 72.45 points from its previous close at 15,864.86 points.

The Sensex was in the positive in the morning session and slipped into the red in the afternoon due to heavy selling pressure in banking stocks. The 30-scrip index touched a high of 16,044.91 points and low of 15,760.53 points in the intra-day.

This is the fourth consecutive day of slide in the benchmark Sensex. The index had tumbled 289 points on Tuesday.

The 50-scrip S&P CNX Nifty of the National Stock Exchange also closed in the red for the fourth straight trading session. The Nifty closed 0.44 percent down at 4,751.30 points, after sliding 1.6 percent on Tuesday.

State Bank of India, the country's largest lender, slumped for the second day after Moody's downgraded its ratings. SBI slumped 4 percent at Rs.1,715.30, after sliding 4.1 percent in the previous day.

Global ratings agency Moody's Investor Service Tuesday downgraded State Bank of India's 'financial strength rating' to D+ from C- citing the low capital adequacy and the bank's recent failure to raise capital and deteriorating asset quality. The agency has also cut the bank's hybrid debt rating to Ba3 from Ba2.

The country's largest private sector lender ICICI Bank closed 2.72 percent down at Rs.778.95.