Nifty holds 7900, Sensex firm; Midcap gains 1%, HDFC down

Nifty holds 7900, Sensex firm; Midcap gains 1%, HDFC down GAIL, Bajaj Auto, TCS, Wipro and Vedanta are top gainers while Sun Pharma, ITC, HDFC, Bharti Airtel and Axis Bank are among the losers.