Air India has settled a "major portion" of dues owed to state-run oil marketing companies and will pay the remainder on Friday, a spokesman for the ailing national carrier said on Thursday.

The oil marketing firms had earlier threatened to halt fuel supplies to Air India, reeling under a debt pile of $4 billion, from Friday for non-payment of dues. 

"We made some payment yesterday, some even today.... We are well within the credit limit of oil marketing companies," the spokesman, who declined to be named, told Reuters.

Earlier, a source at one of the state refiners with direct knowledge of the developments said Air India owes more than 47 billion rupees ($954 million) to Indian Oil Corp, Hindustan Petroleum Corp and Bharat Petroleum Corp.

The airline, banking on government support to survive, has put itself under cash-and-carry mode since Jan. 24, but is yet to clear previous dues, the source said. "How can we continue to sell to them? We are incapable of extending further credit," the source said.

Finances of Indian state refiners are already under pressure for selling diesel, kerosone, and cooking gas at government-fixed cheaper rates.

Airlines received some breather on Wednesday after state refiners cut jet fuel prices by up to 3.1 percent. Jet fuel in the country is still about 55-60 percent costlier than the global average.