"As regards to recovery of outstanding dues, BSNL could recover Rs 320 million from bank guarantees (BG) and balance will be recovered after reconciliation of some other BGs held by us or by BGs held by Government of India or through legal process," Shrivastava said.
Aircel did not respond to an e-mail query.
In its communication to the DoT, BSNL said that following Aircel and Dishnet Wireless filing for bankruptcy, the state-owned telecom corporation had moved swiftly to recover the outstanding amounts through follow-ups and invoking available bank guarantees furnished by them.
The outstanding dues related to various arrangements such as inter-operator settlements like call connect usage charges, tower sharing and intra-circle roaming pacts.
BSNL has said that while it has been able to recover Rs 320 million, the net outstanding amount now stands at Rs 420 million as of March 28, 2018.
The company has said it is exploring other options, including legal remedies, for recovering balance amount.
It has also sought the government's intervention for recovering the balance outstanding dues "by way of setting off any excess amounts of the company that may be available with the Department of Telecommunications".
Aircel announced in February that it has filed for bankruptcy. The telecom operator had said that intense competition following the disruptive entry of a new player, legal and regulatory challenges, high level of unsustainable debt and increased losses had together caused significant "negative business and reputational impact" on the company.
Aircel had also stated that it believes resolution process under the Insolvency and Bankruptcy Code is an "appropriate recourse" given the circumstances.
BSNL's Shrivastava said that the telecom corporation has been able to port in about 3.5 million Aircel customers. As per the latest report by telecom regulator, BSNL had 9.40 per cent share of mobile services market as on January 31 and added 396,000 customers during that month.
The corporation's losses stood at Rs 47.93 billion during 2016-17, lower than Rs 48.59 billion in 2015-16 and Rs 82.35 billion in 2014-15.