The foreign debt of telecom operators such as Bharti Airtel and Reliance Communications might weigh even more as the rupee depreciates.
Bharti Airtel, which acquired the African operations of Zain Telecommunications last year, had a net debt of $13.4 billion at the end of the first quarter of the current financial year.
"About 70 per cent of Bharti's debt is on a floating interest rate and 90 per cent of that is dollar debt," said Bhavesh Gandhi, telecom analyst at IndiaInfoline.
The rupee has depreciated against the dollar by around 10 per cent since August.
This would affect interest cost and repayments.
For Bharti, which gets revenue from its African operation, and has payment liabilities, this will have an effect, analysts said.
A Mumbai-based brokerage, which didn't want to be identified, said they'd estimated a hit of Rs 500 crore (Rs 5 billion) on Bharti Airtel's net profit in the second quarter, and a Rs 400 crore (Rs 4 billion) impact on the net profit of Reliance Communications for the the same period, due to the rupee depreciation.
Many telecom companies used external commercial borrowing to re-finance the debt they'd taken for buying 3G (third-generation) spectrum.
"The repayment and maturity of these loans, however, will come at a much later date. So, currently, their effect is minimal," said an analyst.
RCom also has huge forex liabilities, as it signed an agreement for an underwritten facility of Rs 8,700 crore (Rs 87 billion) from China Development Bank.
Idea Cellular, which has only around 26 per cent of its loan book in foreign currencies, will be impacted the least.
Traditionally, a major part of the capital expenditure of telecom companies, of around 80 per cent, consists of foreign payments.
Experts say a number of companies might have to renegotiate their loan books with bankers.
In the long term, analysts feel it would not have much effect, as many expect this depreciation would not go on for the long term and that the Reserve Bank would step in and arrest it.
And, telecom operators' margins are expected to improve, after all the three listed companies announced rate increases.
They say that as free cash flows improve, increased debt concerns would be low.
"The market is focused more on operational performance of companies," said Gandhi.