Indian operators Bharti Airtel, Vodafone Essar and Idea Cellular have demanded that their 3G licence fees be refunded if the government goes ahead with plans to outlaw national roaming agreements between 3G operators.

In a joint letter to the Indian prime minister, the heads of the three firms claim that the government had given “pre-auction confirmation” that 3G roaming would be allowed and that to ban it would be in breach of contract. “In that eventuality,” the letter says, “we request that our spectrum auction payments be refunded to us, with interest, along with compensation for all the capital investments made by us.”

India’s Department of Telecoms (DoT) had earlier ruled that a national 3G roaming agreement between Bharti, Vodafone and Idea is illegal, which could see the three operators slapped with fines in every region where the deal is in place. The body claims that the agreement violates laws around spectrum sharing and MVNOs, both of which are not permitted under existing rules.

Such roaming deals are seen as a way for the operators to offer a nationwide 3G service as none were able to secure 3G spectrum covering the entire country at auction last year. Bharti, Vodafone and Idea won 3G airwaves in 13, 9 and 11 circles, respectively, and their pact ensured that customers could access 3G services even in regions where they didn’t hold spectrum.

In their letter, the operators say their licences were specifically amended in 2008 to incorporate the right to do inter-circle roaming without any caveat or restriction of technology or spectrum. They also point out that such an agreement enhances competition and consumer choice and, so, it is “powerfully in the interest of consumers.”

However, the Telecom Regulatory Authority of India (TRAI) supports DoT’s view, saying such roaming pacts on sharing spectrum seem to be a “violation of the terms and conditions of the licence.”