It was up 82 points in early trade amidst optimism over economic growth prospects and the government's resolve to use the ordinance route to push more economic reforms.
The BSE's 30-stock benchmark was down 83.44 points, or 0.30 per cent at 27,312.29 at mid-session as profit-booking in bluechips reversed an early rising trend.
Major losers that pulled down the Sensex and NSE's Nifty were Tata Steel, RIL, Sesa Sterlite, Hero MotoCorp, Bharti Airtel, ONGC, Coal Indiam, GAIL, Hndalco, Tata MOtors, Bajaj Auto, HDFC Bank, ICICI Bank, SBI, ITC and Axis Bank.
The Nifty fell by 25.75 points, or 0.31 per cent, to 8,220.55 after rising to 8,268.25 at the outset.
More From This Section
Brokers said selling by participants in bluechip stocks that recently logged gains and a weak trend at other Asian markets, led to the fall in markets at mid-session.
They said foreign funds winding down for the end of the year, also dampened trading sentiments.
Asian stocks were mostly trading lower following a sharp selloff in commodities and caution over political uncertainty in Greece.
Key benchmark indices in China, Hong Kong, Japan, and South Korea fell by 0.4 pct to 0.91 pct. Key benchmark indices in Indonesia, Taiwan and Singapore rose 0.02 pct to 0.14 pct.