Shares in Bharti Airtel fall 5 percent as regulatory concerns resurface ahead of a ministerial panel meeting on mobile spectrum auction later in the day.
Mobile permits for Bharti and Vodafone Group Plc's
The companies have also opposed a government plan for refarming -- or replacing premium quality airwaves with relatively less-efficient airwaves -- unless the carriers buy back the premium airwaves at double the price of the less-efficient band.
"Refarming would hit Vodafone and Bharti the most," said an analyst tracking the sector at a foreign brokerage house.
Bharti also faces government fees of more than $1 billion in airwave surcharges and fines, although most of the payouts have been deferred pending court verdicts.
Some profit-taking from Tuesday's 4.2 percent gain is also seen contributing to Bharti's share fall, dealers say.