The roaming pact among telecom companies for 3G services, which is in violation of licence norms, would lead to significant loss of revenue for the government, according to the Telecom Ministry.

There may also be an impact on revenues from spectrum usage charge collected from operators, according to an internal note prepared by the Department of Telecom (DoT).

The ministry is also likely to send this information to Prime Minister Manmohan Singh.

Recently, the chiefs of three leading telecom firms – Bharti, Idea and Vodafone -- in a jointly singed letter had sought the Prime Minister''s intervention in the dispute over 3G roaming pact, or else they threatened to surrender spectrum.

"During the process of auction, on a query from a participant, a clarification was issued intimating that the customers of those operators who do not win 3G spectrum in a service area, can allow their customers to roam on the 3G network of other operator who has won the 3G spectrum... this arrangement is in the nature of mobile virtual network operator than roaming," the note said.''

Sector regulator Trai and the Law Ministry have already termed the roaming pact among these players as illegal, saying this tantamounts to spectrum sharing which is not allowed as per the policy.

"The amendment also indicates that in case of misuse of the spectrum, the allotment of spectrum can be revoked," the note added.

In the auction for 3G spectrum, held last year which had fetched over Rs 68,000 crore for the government, the operators had won certain circles. Later, they entered into roaming pacts with each other for circles in which they could not win the bid.

Besides these players, others like Tatas and Aircel have also entered into similar agreements for various circles.