Sensex ended the session at 85,102.69, down 609.68 points or 0.71 per cent. The 30-share index started lower at 85,624.84 against last session's closing of 85,624.84. The index extended the loss further amid overall selling to touch an intra-day low at 84,875.59. Nifty closed 25,960.55, down 225.90 points or 0.86 per cent.