Bharti Airtel shares fall 2.4% ahead of a meeting of the group of ministers later in the day that will decide on the base price for an upcoming 2G airwave auction and establish other rules.
The auction follows a Supreme Court order to revoke all permits awarded in the scandal-tainted 2008 sale.
According to a financial daily, the telecoms ministry has proposed in an inter-governmental note to make it compulsory for all operators to match the auction-determined price for their existing 2G airwaves for the remaining period of their licences.
The daily says the measures would cost the sector Rs 1.2 lakh crore, citing "industry calculations."
Reliance Communications falls 0.7%, Idea Cellular shares down 0.1%.
