Undeterred by the defiance shown by the cellular operators to its authority, telecom regulator Trai warned of strict action in case they failed to provide interconnection for WLL-based mobile services of basic telecom companies within 24 hours.

The warning came within hours of Cellular Operators Association of India charging Telecom Regulatory Authority of India with showing "bias and favouritism" towards some telecom companies for their limited mobile services based on Wireless in Local Loop technology and threatening not to comply with the regulator's directive on interconnect.

Charging COAI with adopting 'pressure tactics', Trai said in a letter to cellular operators including Bharti, Hutchinson and IDEA (a venture between Tatas, Birlas and AT&T), "if in 24 hours the traffic is not through, the authority will take action."

In a letter addressed to Narendra Gupta of Bharti Cellular, Trai said, "You were directed by the authority under Section 13 of TRAI (Amendment) Act 2000 to ensure completion of calls originating from Tata Teleservices network and terminating in your network with immediate effect."

"Selective blocking of calls is highly objectionable and violative of the licence agreement as well as the regulations relating to interconnection and quality of services issued by Trai from time to time," the letter said, adding "clearly, the practice (of blocking calls) is anti-competitive and anti consumer."

The directive of January 9, must, therefore be complied without any further delay and blocking of calls reaching respective network must stop forthwith, the regulator said adding, "should you (Bharti) wish to make any submission in this regard, it may be made after the directive has been complied with."

When contacted Bharti officials said they had not received the Trai communication.