Kingfisher Airlines has taken one more step toward the edge, with the Indian airline losing its flying permit after a deadline to renew its suspended license expired.

The debt-ridden carrier has been grounded since October after repeated strikes by employees over unpaid wages.

Kingfisher is believed to have debts of $US1.4 billion, with lenders refusing to give the fresh loans it would need to return to the skies.

Civil Aviation director general Arun Mishra confirmed the flying permit had lapsed after Kingfisher failed to provide additional details on operational funding.

Owned by billionaire Vijay Mallya, Kingfisher has made annual losses for five years.

The airline has not been able to pay its dues to staff, airports, tax agencies and its lenders.