India, Sept. 10 -- Falling for the third straight day, benchmark stock index Sensex tumbled 813 points to a three-month low, and the Nifty settled below 23,450 following selling in IT, FMCG, financial services and oil & gas shares, as escalating tensions in West Asia drove crude oil to over $100 per barrel.

The 30-share BSE Sensex tanked 813.35 points, or 1.08 per cent, to settle at the day's low of 74,764.23, also the lowest closing level in nearly three months.

The 50-share NSE Nifty declined 203.60 points, or 0.86 per cent, to end at a nearly three-month low of 23,431.50. The index had closed near this level on June 11 previously.

Among the 30 Sensex firms, HCL Tech fell the most, down 4.55 per cent. Infosys dropped 4.43 per cent, T...