SINGAPORE - Private Indian carrier Jet Airways, laden with debt, has suspended both its flights to and from Singapore, with no indication of when or whether the services will resume.

Passengers will be refunded their ticket prices, sources told The Straits Times on Thursday (April 11).

In an advisory posted on its Facebook page, Changi Airport said: "Jet Airways (9W) has suspended its services to and from Singapore until further notice. Passengers are advised to contact their booking agent or the airline directly (info@jetairways.com) for available options."

At its peak, Jet Airways was operating nine services a day to and from Singapore; three each from New Delhi and Mumbai, two from Bangalore and one from Pune.

But it has been shrinking its international and domestic operations as its debts piled up.

From nine, the number of daily services dropped to six and then to two about a month ago.

The airline could not be contacted for comments but The Straits Times understands its Singapore office at Changi Airport continues to operate with 13 staff.

Without Jet Airways, the reduced competition could result in higher fares for travellers between Singapore and India, experts said.

Replacing the flights will not be easy, they added.

The reason is the number of flights between countries and who operates them are typically determined by government-to-government air services agreements.

India would be reluctant to let Singapore Airlines, for instance, increase its services as this would reduce the influence of Indian carriers in the market, the experts said.

From a high of about 120 aircraft, Jet Airways, which has struggled with declining profits in the last few years, is down to fewer than 30 planes.

It owes various lenders 8,000 crore rupees (S$1.6 billion).

In March, its founder Naresh Goyal and his wife Anita stepped down from the board, ceding majority control to a consortium of banks.

Indian media are reporting that Jet Airways has received an expression of interest from four companies to buy a stake in the airline.

They are believed to be Etihad Airways PJSC, National Investment and Infrastructure Fund (NIIF), plus private equity firms TPG Capital and Indigo Partners.