Shares of Bharti Airtel jumped as much as 10 per cent, and rival Vodafone Idea Ltd gained as much as 8 per cent as TDSAT has set aside TRAI ruling on predatory pricing.

The Telecom Disputes Settlement and Appellate Tribunal (TDSAT) had on December 13 set aside the Telecom Regulatory Authority of India's (TRAI) rule on predatory pricing for lack of transparency in the guidelines over determining market share and rates of services.

The TDSAT judgment comes as a major relief to Bharti Airtel and Vodafone Idea which had in March challenged the amendment made by TRAI to the telecommunication tariff order. TDSAT has ordered TRAI to rework the predatory pricing rule within six months.

It has also set aside a rule in TRAI predatory pricing regulation that required top telcos to report all tariffs in the interests of transparency and non-discrimination.

Bharti Airtel and Vodafone Idea posted biggest intraday percentage gains since November 16. S&P BSE Telecom index was up 5 per cent.