Bharat Sanchar Nigam Ltd and Mahanagar Telephone Nigam Ltd threatened to deny access to cellular operators if they did not carry calls from limited mobility subscribers through their networks.

This will mean that cell users will be able to connect only to other cell users and not to the 40-million fixed-line users or the 1 million cell users on Dolphin and CellOne.

The Telecom Regulatory Authority of India, meanwhile, decided to issue notices to cell operators for defying the 24-hour deadline to interconnect with limited mobility operators.

The regulator will issue the notice on Thursday, giving cell firms 72 hours to explain why punitive measures should not be initiated against them. The regulator will also give a hearing to the cell operators.

In a letter to cellular operators, BSNL and MTNL said they could not selectively block calls transiting through their networks.

Limited mobility operators like Tata Teleservices and HFCL route calls to cellular subscribers through BSNL and MTNL in the absence of direct connectivity with cellular networks.

While the punitive measures are still being discussed, senior Trai officials said as per the Trai Act, the operators could be asked to pay a lumpsum of Rs 200,000 in addition to Rs 100,000 per day till the operators complied with Trai's January 9 order.

Trai has also given 24 hours to Spice Telecom and Airtel in Punjab to revive the interconnection with Himachal Futuristic Communication Ltd. Spice had snapped its interconnection with HFCL's limited mobility users on Wednesday.

Cell operators met on Thursday to formulate their response to Trai's 24-hour deadline. They said the regulator's order was blatantly "illegal".

"It is shocking that Trai wants to meet us after issuing a showcause notice. It chose not to respond to our earlier request for a hearing," said an operator.

Reacting to the letter, a cellular operator said, "Clearly, any action by MTNL or BSNL is motivated by political pressure. If Trai's order to transmit calls is implemented, it will ensure that they will never interconnect directly. There could be nothing more blatant than this." He said the industry would soon respond to BSNL's letter.