Key stock market indices fell for a third straight session on Thursday, as global sentiment soured after minutes of the US central bank's last policy meeting pointed to aggressive rate hikes and investors awaited cues from the Reserve Bank of India's policy meeting on Friday.

The NSE Nifty 50 index was down 0.5 per cent at 17,745, while the S&P BSE Sensex fell 0.49 per cent to 59,319.48 in the opening session.

Minutes of the Fed's March 15-16 meeting, released on Wednesday, showed deepening concern among policymakers that inflation had broadened through the economy and need for tighter monetary policy.

Investors now await the outcome of the Reserve Bank of India's (RBI) three-day monetary policy meeting due Friday morning amid rising concerns of surging inflation.

Shares of Zee Entertainment fell more than one per cent after US investment firm Invesco said on Wednesday it plans to cut its stake in Zee by more than a third to 11 per cent.

The Nifty Bank index fell 0.5 per cent and the finance index dropped 0.7 per cent. Both the indexes were down for a third straight day after gaining more than 4 per cent on Monday.