In thin trading, the BSE benchmark Sensex ended 21 points lower today, dragged down mainly by HDFC Bank, Hero MotoCorp and Bajaj Auto, which fell in the range of 1-3 per cent.
The 30-share Sensex, which had lost 56 points in the previous session, fell 20.62 points or 0.12 per cent to 17,130.67.
The 50-share National Stock Exchange index Nifty fell 13 points or 0.25 per cent to 5,189 as the stocks of power and realty sectors suffered losses.
Yesterday, S&P had lowered the sovereign credit outlook from stable to negative on risks from slower economic growth and a widening budget deficit.
Brokers said the falling trend was also influenced by factors such as funds cutting their pending positions as derivatives for April series expired and a weak opening in European stock markets.
They also said that with the expiry in the derivatives segment, buying activity almost dried up and reduced the trading volumes to an extent.
Major losers in Sensex that have lost over three per cent fall include Hero MotoCorp, Bajaj Auto, Tata Motors, Maruti Suzuki, GAIL India, Hindalco, DLF Ltd, Tata Power, NTPC, Bharti Airtel, State Bank of India and Sterlite Industries.
However, the two most influential stocks on the index with nearly 20 per cent combined weightage ended higher today.
Reliance Industries gained 1.24 per cent to Rs 745.45 and Infosys closed 0.4 per cent up at Rs 2,358.20, cushioning the downtrend.