Seeking Rs 55 crore from Airtel and Vodafone for routing unidentified calls on its network, public sector BSNL has moved the Supreme Court which asked the private operators file their replies.

A bench headed by Chief Justice S H Kapadia issued notice to Bharti Airtel and Vodafone Essar Gujarat directing them to file their replies.

The apex court further said that it would hear BSNL's plea later, along with a similar case where the state-owned firm is in dispute with Reliance Communications.

BSNL had asked Bharti Airtel and Vodafone to pay more than Rs 90 crore for routing calls with non-Caller Line Identification (CLI), incomplete CLI and unauthorised CLI from its Wireless in local loop, or WLL and basic landline phones between May 2003 to August 2005.

BSNL issued disconnection notice to the operators, which was challenged by them before the telecom tribunal TDSAT. The tribunal, passing an interim order on May 29, 2008, directed Airtel to deposit a sum of Rs 35 crore.

BSNL said that as per the Interconnect Agreement with the private telcos, it is entitled to charge in highest slab, which is for incoming ISD calls.

However, on February 11, 2010 Telecom Disputes Settlement and Appellate Tribunal passed its final order and set aside PSU's demand.

The order was challenged by BSNL today in the apex Court.

It has contended that "demand raised by BSNL for the relevant period are legal and BSNL is fully entitled to recover... even the interconnect agreements signed in the year 2002 (between BSNL and Bharti) entitles it to make and raise demand".

BSNL added, "... calls with regard to non-CLI, incomplete CLI or unauthorised CLI or wrong hand of call shall be liable to be charges at the highest slab, which is rates applicable to the IUC of incoming ISD Call"

It further submitted, "any handover of non-CLI, incomplete CLI or unauthorised CLI etc has a direct impact on the amount of IUC payable to BSNL and it is fully justified and entitled to raise demands to recover all its dues from the respondent".