Bharti Airtel's net profit for Q1 fell as much as 75% to 367 crore for the quarter ended on June 30.
The company's revenue fell 14 percent to Rs 21,958 crore from a year earlier as data and voice rates fell.
Profit on a consolidated basis, which includes the company's Africa operations and its Indian satellite TV business among others, fell to Rs 367 crore ($57.01 million) in the three months to June 30, while revenues fell 14 percent to Rs 21,958 crore, Reuters reported on Tuesday.
India's top telecom operator, Airtel posted smallest profit since December 2012, as a price war sparked by Mukesh Ambani's Reliance.
Reliance Jio, backed by Mukesh, has shaken India's telecom industry since it was launched a year ago by offering months of free services and sharply discounted plans, battering the fortunes of established rivals such as Bharti Airtel and Idea Cellular.
The pricing disruption in the Indian telecom market caused by the entry of a new operator has led to industry revenue declines and created further stress on sector profitability, cash flows and leverage, Gopal Vittal, MD and CEO, India & South Asia, said in a company statement.
Price wars and stiff competition have sparked off consolidation in the telecom industry, with Vodafone Group's Indian unit and Idea Cellular merged operations earlier this year. Bharti Aritel has also taken over the operations of Norwegian telecom company Telenor in six Indian states.